feat: implement filter presets and view state persistence across dashboard, run details, product list, and stalker explorer

- Added functionality to save, update, and apply filter presets for various views.
- Introduced local storage management for persisting view states across sessions.
- Enhanced dashboard, run details, product list, and stalker explorer components to utilize saved filter presets.
- Updated UI to include controls for managing filter presets.

.abacusai/config.json

@@ -25,6 +25,9 @@
       "Bash(git --no-pager diff -- src/web/frontend.tsx src/web/styles.css 2>&1 || true)",
       "Bash(bun run build:web 2>&1 || true)",
       "Bash(bun run build:web 2>&1 || true)",
+      "Bash(bun run build:web 2>&1 || true)",
+      "Bash(bun run build:web 2>&1 || true)",
+      "Bash(bun run build:web 2>&1 || true)",
       "Bash(bun run build:web 2>&1 || true)"
     ]
   },

src/server.ts

@@ -3,10 +3,7 @@ import * as XLSX from "xlsx";
 import { normalizeAsin } from "./asin.ts";
 import { db, client } from "./db/index.ts";
 import { eq } from "drizzle-orm";
-import {
+import { analysisRevisions, productDistributorResearch } from "./db/schema.ts";
-  analysisRevisions,
-  productDistributorResearch,
-} from "./db/schema.ts";
 import { insertObservation, refreshRunStats } from "./db/persistence.ts";
 import { config } from "./config.ts";
 import {
@@ -46,7 +43,10 @@ async function pgGet<T extends Record<string, unknown>>(
   query: string,
   params: unknown[] = [],
 ): Promise<T | null> {
-  const rows = await client.unsafe<T[]>(toPostgresSql(query), params as never[]);
+  const rows = await client.unsafe<T[]>(
+    toPostgresSql(query),
+    params as never[],
+  );
   return (rows[0] as T) ?? null;
 }
 
@@ -54,7 +54,10 @@ async function pgAll<T extends Record<string, unknown>>(
   query: string,
   params: unknown[] = [],
 ): Promise<T[]> {
-  return client.unsafe<T[]>(toPostgresSql(query), params as never[]) as unknown as T[];
+  return client.unsafe<T[]>(
+    toPostgresSql(query),
+    params as never[],
+  ) as unknown as T[];
 }
 
 async function pgRun(query: string, params: unknown[] = []): Promise<number> {
@@ -127,7 +130,10 @@ function safeSort(
 }
 
 function splitRawUpcValues(input: string): string[] {
-  return input.split(/[\s,;|]+/).map((v) => v.trim()).filter(Boolean);
+  return input
+    .split(/[\s,;|]+/)
+    .map((v) => v.trim())
+    .filter(Boolean);
 }
 
 function collectUpcs(value: unknown, target: string[]): void {
@@ -288,7 +294,13 @@ async function getRuns(filters: URLSearchParams) {
     [...params, pageSize, offset],
   );
   const total = Number(totalRow?.total ?? 0);
-  return { items, page, pageSize, total, totalPages: Math.max(1, Math.ceil(total / pageSize)) };
+  return {
+    items,
+    page,
+    pageSize,
+    total,
+    totalPages: Math.max(1, Math.ceil(total / pageSize)),
+  };
 }
 
 async function getRun(runId: number) {
@@ -412,7 +424,11 @@ const ITEM_SORTS: Record<string, string> = {
 async function getRunItems(runId: number, filters: URLSearchParams) {
   const { page, pageSize, offset } = pageInput(filters);
   const { where, params } = itemFilters(filters, runId);
-  const orderBy = safeSort(filters.get("sort"), ITEM_SORTS, "monthly_sold DESC NULLS LAST, asin ASC");
+  const orderBy = safeSort(
+    filters.get("sort"),
+    ITEM_SORTS,
+    "monthly_sold DESC NULLS LAST, asin ASC",
+  );
   const totalRow = await pgGet<{ total: string }>(
     `SELECT COUNT(*) AS total FROM (${ITEM_ROWS}) item_rows ${where}`,
     params,
@@ -422,29 +438,60 @@ async function getRunItems(runId: number, filters: URLSearchParams) {
     [...params, pageSize, offset],
   );
   const total = Number(totalRow?.total ?? 0);
-  return { items, page, pageSize, total, totalPages: Math.max(1, Math.ceil(total / pageSize)) };
+  return {
+    items,
+    page,
+    pageSize,
+    total,
+    totalPages: Math.max(1, Math.ceil(total / pageSize)),
+  };
 }
 
 async function exportRunItems(runId: number, filters: URLSearchParams) {
   const { where, params } = itemFilters(filters, runId);
-  const orderBy = safeSort(filters.get("sort"), ITEM_SORTS, "monthly_sold DESC NULLS LAST, asin ASC");
+  const orderBy = safeSort(
+    filters.get("sort"),
+    ITEM_SORTS,
+    "monthly_sold DESC NULLS LAST, asin ASC",
+  );
   const rows = await pgAll<Record<string, unknown>>(
     `SELECT * FROM (${ITEM_ROWS}) item_rows ${where} ORDER BY ${orderBy}`,
     params,
   );
   const headers = [
-    "run_id", "asin", "product_name", "brand", "category", "unit_cost",
+    "run_id",
-    "current_price", "avg_price_90d", "sales_rank_avg_90d", "seller_count",
+    "asin",
-    "amazon_is_seller", "amazon_buybox_share_pct_90d", "monthly_sold",
+    "product_name",
-    "sellability_status", "verdict", "confidence", "reasoning", "fetched_at",
+    "brand",
+    "category",
+    "unit_cost",
+    "current_price",
+    "avg_price_90d",
+    "sales_rank_avg_90d",
+    "seller_count",
+    "amazon_is_seller",
+    "amazon_buybox_share_pct_90d",
+    "monthly_sold",
+    "sellability_status",
+    "verdict",
+    "confidence",
+    "reasoning",
+    "fetched_at",
   ];
-  return [headers.join(","), ...rows.map((row) => headers.map((h) => escapeCsvValue(row[h])).join(","))].join("\n");
+  return [
+    headers.join(","),
+    ...rows.map((row) => headers.map((h) => escapeCsvValue(row[h])).join(",")),
+  ].join("\n");
 }
 
 async function getProducts(filters: URLSearchParams) {
   const { page, pageSize, offset } = pageInput(filters);
   const { where, params } = itemFilters(filters);
-  const orderBy = safeSort(filters.get("sort"), ITEM_SORTS, "fetched_at DESC NULLS LAST, asin ASC");
+  const orderBy = safeSort(
+    filters.get("sort"),
+    ITEM_SORTS,
+    "fetched_at DESC NULLS LAST, asin ASC",
+  );
   const base = `
     SELECT product.asin, product.asin AS product_asin,
       latest.item_id, latest.run_id AS "runId", latest.process_type AS "processType",
@@ -466,23 +513,28 @@ async function getProducts(filters: URLSearchParams) {
       LIMIT 1
     ) latest ON TRUE`;
   const total = Number(
-    (await pgGet<{ total: string }>(
+    (
+      await pgGet<{ total: string }>(
         `SELECT COUNT(*) AS total FROM (${base}) products ${where}`,
         params,
-    ))?.total ?? 0,
+      )
+    )?.total ?? 0,
   );
   const items = await pgAll(
     `SELECT * FROM (${base}) products ${where} ORDER BY ${orderBy} LIMIT ? OFFSET ?`,
     [...params, pageSize, offset],
   );
-  return { items, page, pageSize, total, totalPages: Math.max(1, Math.ceil(total / pageSize)) };
+  return {
+    items,
+    page,
+    pageSize,
+    total,
+    totalPages: Math.max(1, Math.ceil(total / pageSize)),
+  };
 }
 
 async function getProduct(asin: string) {
-  const product = await pgGet(
+  const product = await pgGet(`SELECT * FROM products WHERE asin = ?`, [asin]);
-    `SELECT * FROM products WHERE asin = ?`,
-    [asin],
-  );
   if (!product) return null;
   const observations = await pgAll(
     `SELECT observation.*, run.type AS run_type
@@ -511,7 +563,9 @@ async function getProduct(asin: string) {
   const distributorResearch = distributorResearchRows.map((row) => {
     const distributors = (() => {
       try {
-        return normalizeDistributorCandidates(JSON.parse(String(row.distributors_json ?? "[]")));
+        return normalizeDistributorCandidates(
+          JSON.parse(String(row.distributors_json ?? "[]")),
+        );
       } catch {
         return [];
       }
@@ -519,7 +573,8 @@ async function getProduct(asin: string) {
     return {
       id: Number(row.id),
       run_item_id: row.run_item_id == null ? null : Number(row.run_item_id),
-      inventory_item_id: row.inventory_item_id == null ? null : Number(row.inventory_item_id),
+      inventory_item_id:
+        row.inventory_item_id == null ? null : Number(row.inventory_item_id),
       provider: String(row.provider ?? ""),
       model: String(row.model ?? ""),
       status: String(row.status ?? ""),
@@ -531,6 +586,37 @@ async function getProduct(asin: string) {
   return { product, observations, analyses, distributorResearch };
 }
 
+async function findLatestRunItemIdByAsin(asin: string): Promise<number | null> {
+  const row = await pgGet<{ id: number }>(
+    `SELECT ri.id
+     FROM run_items ri
+     WHERE ri.product_asin = ?
+     ORDER BY ri.id DESC
+     LIMIT 1`,
+    [asin],
+  );
+  return row?.id == null ? null : Number(row.id);
+}
+
+async function reanalyzeStalkerProductByAsin(
+  asin: string,
+  useClaude = USE_CLAUDE,
+) {
+  const runItemId = await findLatestRunItemIdByAsin(asin);
+  if (runItemId == null) {
+    throw new Error("Stalker product item not found");
+  }
+  return reanalyzeRunItem(runItemId, useClaude);
+}
+
+async function findDistributorsForStalkerProductByAsin(asin: string) {
+  const runItemId = await findLatestRunItemIdByAsin(asin);
+  if (runItemId == null) {
+    throw new Error("Stalker product item not found");
+  }
+  return findDistributorsForStalkerProduct(runItemId);
+}
+
 async function reanalyzeRunItem(itemId: number, useClaude = USE_CLAUDE) {
   const row = await pgGet<Record<string, any>>(
     `SELECT ri.id, ri.run_id, ri.product_asin AS asin, r.type,
@@ -551,7 +637,9 @@ async function reanalyzeRunItem(itemId: number, useClaude = USE_CLAUDE) {
   );
   if (!row) throw new Error("Run item not found");
   if (row.type === "supplier_upc") {
-    throw new Error("Supplier scoring revisions are produced by the supplier pipeline");
+    throw new Error(
+      "Supplier scoring revisions are produced by the supplier pipeline",
+    );
   }
   const record: ProductRecord = {
     asin: row.asin,
@@ -592,15 +680,18 @@ async function reanalyzeRunItem(itemId: number, useClaude = USE_CLAUDE) {
     spApi: spApi as SpApiData,
     fetchedAt: new Date().toISOString(),
   };
-  const verdict =
+  const verdict = (await analyzeProducts([enriched], { useClaude }))[0] ?? {
-    (await analyzeProducts([enriched], { useClaude }))[0] ?? {
     asin: row.asin,
     verdict: "SKIP" as const,
     confidence: 0,
     reasoning: "LLM analysis returned no verdict",
   };
   const result: AnalysisResult = { product: enriched, verdict };
-  const observationId = await insertObservation(row.run_id, result, "reanalysis");
+  const observationId = await insertObservation(
+    row.run_id,
+    result,
+    "reanalysis",
+  );
   await db.insert(analysisRevisions).values({
     runItemId: itemId,
     observationId,
@@ -611,7 +702,12 @@ async function reanalyzeRunItem(itemId: number, useClaude = USE_CLAUDE) {
     analyzedAt: new Date(enriched.fetchedAt),
   });
   await refreshRunStats(row.run_id);
-  return { itemId, runId: row.run_id, asin: row.asin, fetchedAt: enriched.fetchedAt };
+  return {
+    itemId,
+    runId: row.run_id,
+    asin: row.asin,
+    fetchedAt: enriched.fetchedAt,
+  };
 }
 
 type DistributorCandidate = {
@@ -630,10 +726,15 @@ function clampDistributorConfidence(value: unknown): number {
   return Math.max(0, Math.min(100, Math.round(parsed)));
 }
 
-function normalizeDistributorCandidates(payload: unknown): DistributorCandidate[] {
+function normalizeDistributorCandidates(
+  payload: unknown,
+): DistributorCandidate[] {
   if (!Array.isArray(payload)) return [];
   return payload
-    .filter((item): item is Record<string, unknown> => item != null && typeof item === "object")
+    .filter(
+      (item): item is Record<string, unknown> =>
+        item != null && typeof item === "object",
+    )
     .map((item) => ({
       name: String(item.name ?? "").trim(),
       website: String(item.website ?? "").trim(),
@@ -641,7 +742,9 @@ function normalizeDistributorCandidates(payload: unknown): DistributorCandidate[
       confidence: clampDistributorConfidence(item.confidence),
       reputation: String(item.reputation ?? "").trim(),
       contactInfo: String(item.contact_info ?? item.contactInfo ?? "").trim(),
-      outreachDraft: String(item.outreach_draft ?? item.outreachDraft ?? "").trim(),
+      outreachDraft: String(
+        item.outreach_draft ?? item.outreachDraft ?? "",
+      ).trim(),
     }))
     .filter((item) => item.name.length > 0 && item.website.length > 0)
     .slice(0, 10);
@@ -650,7 +753,7 @@ function normalizeDistributorCandidates(payload: unknown): DistributorCandidate[
 function extractJsonArrayFromText(text: string): string {
   const trimmed = text.trim();
   const fence = trimmed.match(/```(?:json)?\s*([\s\S]*?)```/i);
-  const candidate = fence ? fence[1]?.trim() ?? "" : trimmed;
+  const candidate = fence ? (fence[1]?.trim() ?? "") : trimmed;
   const start = candidate.indexOf("[");
   const end = candidate.lastIndexOf("]");
   if (start >= 0 && end > start) {
@@ -659,11 +762,14 @@ function extractJsonArrayFromText(text: string): string {
   return candidate;
 }
 
-async function requestClaudeDistributorCandidates(context: Record<string, unknown>) {
+async function requestClaudeDistributorCandidates(
+  context: Record<string, unknown>,
+) {
   if (!config.anthropicApiKey) {
     throw new Error("Missing required env var: ANTHROPIC_API_KEY");
   }
-  const model = (config.anthropicModel ?? "claude-sonnet-4-6").trim() || "claude-sonnet-4-6";
+  // const model = (config.anthropicModel ?? "claude-sonnet-4-6").trim() || "claude-sonnet-4-6";
+  const model = "claude-sonnet-4-6";
   const system = [
     "You are a wholesale sourcing researcher who identifies authorized U.S. distributors for Amazon products.",
     "For each candidate you research their reputation, locate real point-of-contact details, and draft a concise cold-outreach message.",
@@ -707,13 +813,19 @@ async function requestClaudeDistributorCandidates(context: Record<string, unknow
   });
   const raw = await response.text();
   if (!response.ok) {
-    throw new Error(`Claude API error ${response.status}: ${raw.slice(0, 300)}`);
+    throw new Error(
+      `Claude API error ${response.status}: ${raw.slice(0, 300)}`,
+    );
   }
   let contentText = "";
   try {
-    const parsed = JSON.parse(raw) as { content?: Array<{ type?: string; text?: string }> };
+    const parsed = JSON.parse(raw) as {
+      content?: Array<{ type?: string; text?: string }>;
+    };
     contentText = (parsed.content ?? [])
-      .filter((block) => block?.type === "text" && typeof block.text === "string")
+      .filter(
+        (block) => block?.type === "text" && typeof block.text === "string",
+      )
       .map((block) => block.text ?? "")
       .join("\n");
   } catch {
@@ -817,7 +929,10 @@ async function findDistributorsForStalkerProduct(runItemId: number) {
       distributorsJson: JSON.stringify(claude.candidates),
       rawResponse: claude.rawResponse,
     })
-    .returning({ id: productDistributorResearch.id, createdAt: productDistributorResearch.createdAt });
+    .returning({
+      id: productDistributorResearch.id,
+      createdAt: productDistributorResearch.createdAt,
+    });
   return {
     asin: row.asin,
     runItemId: runItemId,
@@ -866,7 +981,10 @@ function stalkerBaseWhere(filters: URLSearchParams, product = false) {
     }
   }
   if (product) {
-    conditions.push("observation.can_sell = true", "observation.sellability_status = 'available'");
+    conditions.push(
+      "observation.can_sell = true",
+      "observation.sellability_status = 'available'",
+    );
     const verdict = filters.get("verdict")?.toUpperCase();
     if (verdict === "FBA" || verdict === "FBM" || verdict === "SKIP") {
       conditions.push("analysis.decision::text = ?");
@@ -936,7 +1054,14 @@ async function getStalkerResults(filters: URLSearchParams) {
     },
     "persisted_inventory_asin_count DESC, last_seen_at DESC, seller_id ASC",
   );
-  const total = Number((await pgGet<{ total: string }>(`SELECT COUNT(*) AS total FROM (${base}) rows`, params))?.total ?? 0);
+  const total = Number(
+    (
+      await pgGet<{ total: string }>(
+        `SELECT COUNT(*) AS total FROM (${base}) rows`,
+        params,
+      )
+    )?.total ?? 0,
+  );
   const items = await pgAll(
     `SELECT * FROM (${base}) rows ORDER BY ${order} LIMIT ? OFFSET ?`,
     [...params, pageSize, offset],
@@ -954,7 +1079,10 @@ async function getStalkerResults(filters: URLSearchParams) {
       sellers: Number(summary?.sellers ?? 0),
       persistedInventoryAsins: Number(summary?.persistedInventoryAsins ?? 0),
     },
-    page, pageSize, total, totalPages: Math.max(1, Math.ceil(total / pageSize)),
+    page,
+    pageSize,
+    total,
+    totalPages: Math.max(1, Math.ceil(total / pageSize)),
   };
 }
 
@@ -1012,8 +1140,16 @@ async function stalkerProducts(filters: URLSearchParams, exportOnly = false) {
     },
     "monthly_sold DESC NULLS LAST, last_seen_at DESC, asin ASC",
   );
-  if (exportOnly) return pgAll(`SELECT * FROM (${base}) products ORDER BY ${order}`, params);
+  if (exportOnly)
-  const total = Number((await pgGet<{ total: string }>(`SELECT COUNT(*) AS total FROM (${base}) products`, params))?.total ?? 0);
+    return pgAll(`SELECT * FROM (${base}) products ORDER BY ${order}`, params);
+  const total = Number(
+    (
+      await pgGet<{ total: string }>(
+        `SELECT COUNT(*) AS total FROM (${base}) products`,
+        params,
+      )
+    )?.total ?? 0,
+  );
   const items = await pgAll(
     `SELECT * FROM (${base}) products ORDER BY ${order} LIMIT ? OFFSET ?`,
     [...params, pageSize, offset],
@@ -1030,12 +1166,19 @@ async function stalkerProducts(filters: URLSearchParams, exportOnly = false) {
       sellers: Number(summary?.sellers ?? 0),
       products: Number(summary?.products ?? 0),
     },
-    page, pageSize, total, totalPages: Math.max(1, Math.ceil(total / pageSize)),
+    page,
+    pageSize,
+    total,
+    totalPages: Math.max(1, Math.ceil(total / pageSize)),
   };
 }
 
-async function exportStalkerProducts(filters: URLSearchParams): Promise<Response> {
+async function exportStalkerProducts(
-  const rows = (await stalkerProducts(filters, true)) as Array<Record<string, any>>;
+  filters: URLSearchParams,
+): Promise<Response> {
+  const rows = (await stalkerProducts(filters, true)) as Array<
+    Record<string, any>
+  >;
   const data = rows.map((row) => ({
     ASIN: row.asin,
     "Amazon URL": `https://amazon.com/dp/${row.asin}`,
@@ -1053,7 +1196,11 @@ async function exportStalkerProducts(filters: URLSearchParams): Promise<Response
     "Run ID": row.runId,
   }));
   const workbook = XLSX.utils.book_new();
-  XLSX.utils.book_append_sheet(workbook, XLSX.utils.json_to_sheet(data), "Sellable Products");
+  XLSX.utils.book_append_sheet(
+    workbook,
+    XLSX.utils.json_to_sheet(data),
+    "Sellable Products",
+  );
   return xlsx(
     XLSX.write(workbook, { type: "array", bookType: "xlsx" }) as ArrayBuffer,
     "stalker-sellable-products.xlsx",
@@ -1082,13 +1229,17 @@ const server = Bun.serve({
     "/stalker": index,
     "/stalker/products": index,
     "/runs/:runId": index,
-    "/api/runs": async (req) => json(await getRuns(new URL(req.url).searchParams)),
+    "/api/runs": async (req) =>
+      json(await getRuns(new URL(req.url).searchParams)),
     "/api/runs/:runId": async (req) => {
       const runId = Number(req.params.runId);
-      if (!Number.isInteger(runId)) return json({ error: "Invalid run identifier" }, 400);
+      if (!Number.isInteger(runId))
+        return json({ error: "Invalid run identifier" }, 400);
       if (req.method === "DELETE") {
         const deleted = await pgRun("DELETE FROM runs WHERE id = ?", [runId]);
-        return deleted ? json({ deletedRun: true }) : json({ error: "Run not found" }, 404);
+        return deleted
+          ? json({ deletedRun: true })
+          : json({ error: "Run not found" }, 404);
       }
       const run = await getRun(runId);
       if (!run) return json({ error: "Run not found" }, 404);
@@ -1106,57 +1257,121 @@ const server = Bun.serve({
     },
     "/api/runs/:runId/items": async (req) => {
       const runId = Number(req.params.runId);
-      if (!Number.isInteger(runId)) return json({ error: "Invalid run identifier" }, 400);
+      if (!Number.isInteger(runId))
+        return json({ error: "Invalid run identifier" }, 400);
       return json(await getRunItems(runId, new URL(req.url).searchParams));
     },
     "/api/runs/:runId/export.csv": async (req) => {
       const runId = Number(req.params.runId);
-      if (!Number.isInteger(runId)) return json({ error: "Invalid run identifier" }, 400);
+      if (!Number.isInteger(runId))
-      return csv(await exportRunItems(runId, new URL(req.url).searchParams), `run-${runId}.csv`);
+        return json({ error: "Invalid run identifier" }, 400);
+      return csv(
+        await exportRunItems(runId, new URL(req.url).searchParams),
+        `run-${runId}.csv`,
+      );
     },
     "/api/run-items/:itemId/reanalyze": async (req) => {
-      if (req.method !== "POST") return json({ error: "Method not allowed" }, 405);
+      if (req.method !== "POST")
+        return json({ error: "Method not allowed" }, 405);
       const itemId = Number(req.params.itemId);
-      if (!Number.isInteger(itemId)) return json({ error: "Invalid run item identifier" }, 400);
+      if (!Number.isInteger(itemId))
+        return json({ error: "Invalid run item identifier" }, 400);
       try {
         return json(await reanalyzeRunItem(itemId));
       } catch (error) {
         const message = error instanceof Error ? error.message : String(error);
-        return json({ error: message }, message === "Run item not found" ? 404 : 500);
+        return json(
+          { error: message },
+          message === "Run item not found" ? 404 : 500,
+        );
       }
     },
-    "/api/products": async (req) => json(await getProducts(new URL(req.url).searchParams)),
+    "/api/products": async (req) =>
+      json(await getProducts(new URL(req.url).searchParams)),
     "/api/products/:asin": async (req) => {
       const asin = normalizeAsin(req.params.asin);
       if (!asin) return json({ error: "Invalid ASIN" }, 400);
       const result = await getProduct(asin);
       return result ? json(result) : json({ error: "Product not found" }, 404);
     },
-    "/api/stalker/results": async (req) => json(await getStalkerResults(new URL(req.url).searchParams)),
+    "/api/stalker/results": async (req) =>
-    "/api/stalker/products": async (req) => json(await stalkerProducts(new URL(req.url).searchParams)),
+      json(await getStalkerResults(new URL(req.url).searchParams)),
-    "/api/stalker/products/export.xlsx": async (req) => exportStalkerProducts(new URL(req.url).searchParams),
+    "/api/stalker/products": async (req) =>
+      json(await stalkerProducts(new URL(req.url).searchParams)),
+    "/api/stalker/products/export.xlsx": async (req) =>
+      exportStalkerProducts(new URL(req.url).searchParams),
     "/api/stalker/products/:runItemId/reanalyze": async (req) => {
-      if (req.method !== "POST") return json({ error: "Method not allowed" }, 405);
+      if (req.method !== "POST")
+        return json({ error: "Method not allowed" }, 405);
       const runItemId = Number(req.params.runItemId);
-      if (!Number.isInteger(runItemId)) return json({ error: "Invalid run item identifier" }, 400);
+      if (!Number.isInteger(runItemId))
-      const provider = new URL(req.url).searchParams.get("provider")?.trim().toLowerCase();
+        return json({ error: "Invalid run item identifier" }, 400);
+      const provider = new URL(req.url).searchParams
+        .get("provider")
+        ?.trim()
+        .toLowerCase();
       const useClaude = provider === "claude";
       try {
         return json(await reanalyzeRunItem(runItemId, useClaude || USE_CLAUDE));
       } catch (error) {
         const message = error instanceof Error ? error.message : String(error);
-        return json({ error: message }, message === "Run item not found" ? 404 : 500);
+        return json(
+          { error: message },
+          message === "Run item not found" ? 404 : 500,
+        );
       }
     },
     "/api/stalker/products/:runItemId/distributors": async (req) => {
-      if (req.method !== "POST") return json({ error: "Method not allowed" }, 405);
+      if (req.method !== "POST")
+        return json({ error: "Method not allowed" }, 405);
       const runItemId = Number(req.params.runItemId);
-      if (!Number.isInteger(runItemId)) return json({ error: "Invalid run item identifier" }, 400);
+      if (!Number.isInteger(runItemId))
+        return json({ error: "Invalid run item identifier" }, 400);
       try {
         return json(await findDistributorsForStalkerProduct(runItemId));
       } catch (error) {
         const message = error instanceof Error ? error.message : String(error);
-        return json({ error: message }, message === "Stalker product item not found" ? 404 : 500);
+        return json(
+          { error: message },
+          message === "Stalker product item not found" ? 404 : 500,
+        );
+      }
+    },
+    "/api/stalker/products/by-asin/:asin/reanalyze": async (req) => {
+      if (req.method !== "POST")
+        return json({ error: "Method not allowed" }, 405);
+      const asin = normalizeAsin(req.params.asin);
+      if (!asin) return json({ error: "Invalid ASIN" }, 400);
+      const provider = new URL(req.url).searchParams
+        .get("provider")
+        ?.trim()
+        .toLowerCase();
+      const useClaude = provider === "claude";
+      try {
+        return json(
+          await reanalyzeStalkerProductByAsin(asin, useClaude || USE_CLAUDE),
+        );
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        return json(
+          { error: message },
+          message === "Stalker product item not found" ? 404 : 500,
+        );
+      }
+    },
+    "/api/stalker/products/by-asin/:asin/distributors": async (req) => {
+      if (req.method !== "POST")
+        return json({ error: "Method not allowed" }, 405);
+      const asin = normalizeAsin(req.params.asin);
+      if (!asin) return json({ error: "Invalid ASIN" }, 400);
+      try {
+        return json(await findDistributorsForStalkerProductByAsin(asin));
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        return json(
+          { error: message },
+          message === "Stalker product item not found" ? 404 : 500,
+        );
       }
     },
     "/api/stalker/purge": async (req) =>
@@ -1168,10 +1383,15 @@ const server = Bun.serve({
         const upcs = await parseUpcsFromRequest(req);
         const error = validateUpcs(upcs);
         if (error) return json({ error }, 400);
-        const items = [...(await mapUpcsToAsins(upcs)).entries()].map(([upc, asin]) => ({ upc, asin }));
+        const items = [...(await mapUpcsToAsins(upcs)).entries()].map(
+          ([upc, asin]) => ({ upc, asin }),
+        );
         return json({ requested: upcs.length, matched: items.length, items });
       } catch (error) {
-        return json({ error: error instanceof Error ? error.message : String(error) }, 400);
+        return json(
+          { error: error instanceof Error ? error.message : String(error) },
+          400,
+        );
       }
     },
     "/api/upc/lookup": async (req) => {
@@ -1180,16 +1400,31 @@ const server = Bun.serve({
         const error = validateUpcs(upcs);
         if (error) return json({ error }, 400);
         const items = [...(await lookupKeepaUpcs(upcs)).values()];
-        return json({ requested: upcs.length, statusCounts: summarizeLookupStatuses(items), items });
+        return json({
+          requested: upcs.length,
+          statusCounts: summarizeLookupStatuses(items),
+          items,
+        });
       } catch (error) {
-        return json({ error: error instanceof Error ? error.message : String(error) }, 400);
+        return json(
+          { error: error instanceof Error ? error.message : String(error) },
+          400,
+        );
       }
     },
     "/api/process/upc-file": async (req) => {
       try {
-        return json(await runUpcFileAnalysis({ ...(await parseUpcFileRequest(req)), manageResources: false }));
+        return json(
+          await runUpcFileAnalysis({
+            ...(await parseUpcFileRequest(req)),
+            manageResources: false,
+          }),
+        );
       } catch (error) {
-        return json({ error: error instanceof Error ? error.message : String(error) }, 400);
+        return json(
+          { error: error instanceof Error ? error.message : String(error) },
+          400,
+        );
       }
     },
   },

src/web/frontend.tsx

@@ -300,6 +300,85 @@ function nextSort(current: SortState, field: string): SortState {
   };
 }
 
+const VIEW_STATE_KEY = "asin-check.view-state.v1";
+const FILTER_PRESETS_KEY = "asin-check.filter-presets.v1";
+
+type SavedFilterPreset = {
+  id: string;
+  name: string;
+  viewKey: string;
+  state: Record<string, unknown>;
+  updatedAt: string;
+};
+
+function readJsonStorage<T>(key: string, fallback: T): T {
+  try {
+    const raw = window.localStorage.getItem(key);
+    if (!raw) return fallback;
+    return JSON.parse(raw) as T;
+  } catch {
+    return fallback;
+  }
+}
+
+function writeJsonStorage<T>(key: string, value: T): void {
+  try {
+    window.localStorage.setItem(key, JSON.stringify(value));
+  } catch {
+  }
+}
+
+function readViewState(viewKey: string): Record<string, unknown> {
+  const all = readJsonStorage<Record<string, Record<string, unknown>>>(VIEW_STATE_KEY, {});
+  const value = all[viewKey];
+  return value && typeof value === "object" ? value : {};
+}
+
+function saveViewState(viewKey: string, state: Record<string, unknown>): void {
+  const all = readJsonStorage<Record<string, Record<string, unknown>>>(VIEW_STATE_KEY, {});
+  all[viewKey] = state;
+  writeJsonStorage(VIEW_STATE_KEY, all);
+}
+
+function listFilterPresets(viewKey: string): SavedFilterPreset[] {
+  const all = readJsonStorage<SavedFilterPreset[]>(FILTER_PRESETS_KEY, []);
+  return all.filter((preset) => preset.viewKey === viewKey);
+}
+
+function saveFilterPreset(viewKey: string, name: string, state: Record<string, unknown>): SavedFilterPreset {
+  const all = readJsonStorage<SavedFilterPreset[]>(FILTER_PRESETS_KEY, []);
+  const normalizedName = name.trim().toLowerCase();
+  const existing = all.find((preset) => preset.viewKey === viewKey && preset.name.trim().toLowerCase() === normalizedName);
+  if (existing) {
+    existing.state = state;
+    existing.updatedAt = new Date().toISOString();
+    writeJsonStorage(FILTER_PRESETS_KEY, all);
+    return existing;
+  }
+  const created: SavedFilterPreset = {
+    id: typeof crypto !== "undefined" && typeof crypto.randomUUID === "function"
+      ? crypto.randomUUID()
+      : `${Date.now()}-${Math.random()}`,
+    name: name.trim(),
+    viewKey,
+    state,
+    updatedAt: new Date().toISOString(),
+  };
+  all.unshift(created);
+  writeJsonStorage(FILTER_PRESETS_KEY, all);
+  return created;
+}
+
+function updateFilterPreset(presetId: string, state: Record<string, unknown>): SavedFilterPreset | null {
+  const all = readJsonStorage<SavedFilterPreset[]>(FILTER_PRESETS_KEY, []);
+  const existing = all.find((preset) => preset.id === presetId);
+  if (!existing) return null;
+  existing.state = state;
+  existing.updatedAt = new Date().toISOString();
+  writeJsonStorage(FILTER_PRESETS_KEY, all);
+  return existing;
+}
+
 function statusBadgeClass(status: string): string {
   if (status === "ok" || status === "completed") return "badge badge-ok";
   if (status === "failed") return "badge badge-failed";
@@ -367,18 +446,90 @@ function Dashboard({
   onOpenStalker: () => void;
   onOpenStalkerProducts: () => void;
 }) {
+  const viewKey = "dashboard";
+  const initialState = useMemo(() => readViewState(viewKey), []);
   const [runs, setRuns] = useState<RunsResponse | null>(null);
   const [loading, setLoading] = useState(false);
-  const [search, setSearch] = useState("");
+  const [search, setSearch] = useState(String(initialState.search ?? ""));
-  const [processType, setProcessType] = useState("");
+  const [processType, setProcessType] = useState(String(initialState.processType ?? ""));
-  const [status, setStatus] = useState("");
+  const [status, setStatus] = useState(String(initialState.status ?? ""));
-  const [startDate, setStartDate] = useState("");
+  const [startDate, setStartDate] = useState(String(initialState.startDate ?? ""));
-  const [endDate, setEndDate] = useState("");
+  const [endDate, setEndDate] = useState(String(initialState.endDate ?? ""));
-  const [page, setPage] = useState(1);
+  const [page, setPage] = useState(Number(initialState.page ?? 1) || 1);
-  const [pageSize, setPageSize] = useState(25);
+  const [pageSize, setPageSize] = useState(Number(initialState.pageSize ?? 25) || 25);
-  const [sort, setSort] = useState<SortState>({ field: "timestamp", direction: "DESC" });
+  const [sort, setSort] = useState<SortState>({
+    field: String(initialState.sortField ?? "timestamp"),
+    direction: initialState.sortDirection === "ASC" ? "ASC" : "DESC",
+  });
   const [refreshTick, setRefreshTick] = useState(0);
   const [deletingKey, setDeletingKey] = useState<string | null>(null);
+  const [presetName, setPresetName] = useState("");
+  const [selectedPresetId, setSelectedPresetId] = useState("");
+  const [presets, setPresets] = useState<SavedFilterPreset[]>(() => listFilterPresets(viewKey));
+
+  function snapshotFilters(): Record<string, unknown> {
+    return {
+      search,
+      processType,
+      status,
+      startDate,
+      endDate,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    };
+  }
+
+  function applyFilterState(state: Record<string, unknown>) {
+    setSearch(String(state.search ?? ""));
+    setProcessType(String(state.processType ?? ""));
+    setStatus(String(state.status ?? ""));
+    setStartDate(String(state.startDate ?? ""));
+    setEndDate(String(state.endDate ?? ""));
+    setPage(Number(state.page ?? 1) || 1);
+    setPageSize(Number(state.pageSize ?? 25) || 25);
+    setSort({
+      field: String(state.sortField ?? "timestamp"),
+      direction: state.sortDirection === "ASC" ? "ASC" : "DESC",
+    });
+  }
+
+  function saveCurrentPreset() {
+    if (!presetName.trim()) return;
+    const saved = saveFilterPreset(viewKey, presetName, snapshotFilters());
+    setPresets(listFilterPresets(viewKey));
+    setSelectedPresetId(saved.id);
+    setPresetName(saved.name);
+  }
+
+  function applySelectedPreset() {
+    if (!selectedPresetId) return;
+    const preset = presets.find((item) => item.id === selectedPresetId);
+    if (!preset) return;
+    applyFilterState(preset.state);
+  }
+
+  function updateSelectedPreset() {
+    if (!selectedPresetId) return;
+    const updated = updateFilterPreset(selectedPresetId, snapshotFilters());
+    if (!updated) return;
+    setPresets(listFilterPresets(viewKey));
+  }
+
+  useEffect(() => {
+    saveViewState(viewKey, {
+      search,
+      processType,
+      status,
+      startDate,
+      endDate,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    });
+  }, [viewKey, search, processType, status, startDate, endDate, page, pageSize, sort]);
 
   const summary = useMemo(() => {
     if (!runs) return { total: 0, fba: 0, fbm: 0, skip: 0 };
@@ -504,6 +655,14 @@ function Dashboard({
             <option value="50">50 / page</option>
             <option value="100">100 / page</option>
           </select>
+          <input value={presetName} onChange={(e) => setPresetName(e.target.value)} placeholder="Preset name" />
+          <select value={selectedPresetId} onChange={(e) => setSelectedPresetId(e.target.value)}>
+            <option value="">Select preset</option>
+            {presets.map((preset) => <option key={preset.id} value={preset.id}>{preset.name}</option>)}
+          </select>
+          <button onClick={saveCurrentPreset}>Save</button>
+          <button disabled={!selectedPresetId} onClick={updateSelectedPreset}>Update</button>
+          <button disabled={!selectedPresetId} onClick={applySelectedPreset}>Apply</button>
         </div>
       </div>
 
@@ -596,21 +755,96 @@ function RunDetails({
   runId: number;
   onBack: () => void;
 }) {
+  const viewKey = `run-details:${runId}`;
+  const initialState = useMemo(() => readViewState(viewKey), [viewKey]);
   const [run, setRun] = useState<RunDetail | null>(null);
   const [results, setResults] = useState<ResultsResponse | null>(null);
   const [loading, setLoading] = useState(true);
-  const [search, setSearch] = useState("");
+  const [search, setSearch] = useState(String(initialState.search ?? ""));
-  const [verdict, setVerdict] = useState("");
+  const [verdict, setVerdict] = useState(String(initialState.verdict ?? ""));
-  const [sellabilityStatus, setSellabilityStatus] = useState("");
+  const [sellabilityStatus, setSellabilityStatus] = useState(String(initialState.sellabilityStatus ?? ""));
   const [amazonSellerFilter, setAmazonSellerFilter] =
-    useState<AmazonSellerFilter>("");
+    useState<AmazonSellerFilter>(initialState.amazonSellerFilter === "yes" || initialState.amazonSellerFilter === "no" ? initialState.amazonSellerFilter : "");
-  const [minConfidence, setMinConfidence] = useState("");
+  const [minConfidence, setMinConfidence] = useState(String(initialState.minConfidence ?? ""));
-  const [maxConfidence, setMaxConfidence] = useState("");
+  const [maxConfidence, setMaxConfidence] = useState(String(initialState.maxConfidence ?? ""));
-  const [page, setPage] = useState(1);
+  const [page, setPage] = useState(Number(initialState.page ?? 1) || 1);
-  const [pageSize, setPageSize] = useState(25);
+  const [pageSize, setPageSize] = useState(Number(initialState.pageSize ?? 25) || 25);
-  const [sort, setSort] = useState<SortState>({ field: "monthly_sold", direction: "DESC" });
+  const [sort, setSort] = useState<SortState>({
+    field: String(initialState.sortField ?? "monthly_sold"),
+    direction: initialState.sortDirection === "ASC" ? "ASC" : "DESC",
+  });
   const [refreshTick, setRefreshTick] = useState(0);
   const [reanalyzing, setReanalyzing] = useState<Record<string, boolean>>({});
+  const [presetName, setPresetName] = useState("");
+  const [selectedPresetId, setSelectedPresetId] = useState("");
+  const [presets, setPresets] = useState<SavedFilterPreset[]>(() => listFilterPresets(viewKey));
+
+  useEffect(() => {
+    saveViewState(viewKey, {
+      search,
+      verdict,
+      sellabilityStatus,
+      amazonSellerFilter,
+      minConfidence,
+      maxConfidence,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    });
+  }, [viewKey, search, verdict, sellabilityStatus, amazonSellerFilter, minConfidence, maxConfidence, page, pageSize, sort]);
+
+  function snapshotFilters(): Record<string, unknown> {
+    return {
+      search,
+      verdict,
+      sellabilityStatus,
+      amazonSellerFilter,
+      minConfidence,
+      maxConfidence,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    };
+  }
+
+  function applyFilterState(state: Record<string, unknown>) {
+    setSearch(String(state.search ?? ""));
+    setVerdict(String(state.verdict ?? ""));
+    setSellabilityStatus(String(state.sellabilityStatus ?? ""));
+    setAmazonSellerFilter(state.amazonSellerFilter === "yes" || state.amazonSellerFilter === "no" ? state.amazonSellerFilter : "");
+    setMinConfidence(String(state.minConfidence ?? ""));
+    setMaxConfidence(String(state.maxConfidence ?? ""));
+    setPage(Number(state.page ?? 1) || 1);
+    setPageSize(Number(state.pageSize ?? 25) || 25);
+    setSort({
+      field: String(state.sortField ?? "monthly_sold"),
+      direction: state.sortDirection === "ASC" ? "ASC" : "DESC",
+    });
+  }
+
+  function saveCurrentPreset() {
+    if (!presetName.trim()) return;
+    const saved = saveFilterPreset(viewKey, presetName, snapshotFilters());
+    setPresets(listFilterPresets(viewKey));
+    setSelectedPresetId(saved.id);
+    setPresetName(saved.name);
+  }
+
+  function applySelectedPreset() {
+    if (!selectedPresetId) return;
+    const preset = presets.find((item) => item.id === selectedPresetId);
+    if (!preset) return;
+    applyFilterState(preset.state);
+  }
+
+  function updateSelectedPreset() {
+    if (!selectedPresetId) return;
+    const updated = updateFilterPreset(selectedPresetId, snapshotFilters());
+    if (!updated) return;
+    setPresets(listFilterPresets(viewKey));
+  }
 
   const anomalies = useMemo(() => {
     if (!results) return [] as ResultItem[];
@@ -755,6 +989,14 @@ function RunDetails({
             <option value="50">50 / page</option>
             <option value="100">100 / page</option>
           </select>
+          <input value={presetName} onChange={(e) => setPresetName(e.target.value)} placeholder="Preset name" />
+          <select value={selectedPresetId} onChange={(e) => setSelectedPresetId(e.target.value)}>
+            <option value="">Select preset</option>
+            {presets.map((preset) => <option key={preset.id} value={preset.id}>{preset.name}</option>)}
+          </select>
+          <button onClick={saveCurrentPreset}>Save</button>
+          <button disabled={!selectedPresetId} onClick={updateSelectedPreset}>Update</button>
+          <button disabled={!selectedPresetId} onClick={applySelectedPreset}>Apply</button>
         </div>
         <div style={{ marginTop: 10 }}>
           <a
@@ -773,7 +1015,7 @@ function RunDetails({
           <div className="anomaly-list" style={{ marginTop: 8 }}>
             {anomalies.slice(0, 8).map((item) => (
               <div key={`anom-${item.asin}-${item.fetched_at}`} className="anomaly-item">
-                {item.product_asin ? <a href={`/products/${item.product_asin}`}>{item.asin}</a> : item.asin}
+                {item.product_asin ? <button onClick={() => onOpenProduct(item.product_asin!, item.item_id)}>{item.asin}</button> : item.asin}
                 {item.verdict ? <span className={verdictBadgeClass(item.verdict)}>{item.verdict}</span> : "-"}
                 <span>{detectAnomaly(item)}</span>
               </div>
@@ -810,7 +1052,7 @@ function RunDetails({
               ) : results?.items.length ? (
                 results.items.map((item) => (
                   <tr key={`${item.asin}-${item.fetched_at}`}>
-                    <td>{item.product_asin ? <a href={`/products/${item.product_asin}`}>{item.asin}</a> : item.asin}</td>
+                    <td>{item.product_asin ? <button onClick={() => onOpenProduct(item.product_asin!, item.item_id)}>{item.asin}</button> : item.asin}</td>
                     <td>{item.verdict ? <span className={verdictBadgeClass(item.verdict)}>{item.verdict}</span> : "-"}</td>
                     <td>{formatNumber(item.monthly_sold)}</td>
                     <td>{formatNumber(item.seller_count)}</td>
@@ -855,17 +1097,83 @@ function RunDetails({
   );
 }
 
-function ProductList({ verdict, onBack }: { verdict: VerdictFilter; onBack: () => void }) {
+function ProductList({ verdict, onBack, onOpenProduct }: { verdict: VerdictFilter; onBack: () => void; onOpenProduct: (asin: string, runItemId: number | null) => void }) {
+  const viewKey = "products";
+  const initialState = useMemo(() => readViewState(viewKey), []);
   const [items, setItems] = useState<ProductListResponse | null>(null);
   const [loading, setLoading] = useState(false);
-  const [search, setSearch] = useState("");
+  const [search, setSearch] = useState(String(initialState.search ?? ""));
-  const [activeVerdict, setActiveVerdict] = useState<VerdictFilter>(verdict);
+  const [activeVerdict, setActiveVerdict] = useState<VerdictFilter>(String(initialState.activeVerdict ?? verdict) as VerdictFilter);
   const [amazonSellerFilter, setAmazonSellerFilter] =
-    useState<AmazonSellerFilter>("");
+    useState<AmazonSellerFilter>(initialState.amazonSellerFilter === "yes" || initialState.amazonSellerFilter === "no" ? initialState.amazonSellerFilter : "");
-  const [page, setPage] = useState(1);
+  const [page, setPage] = useState(Number(initialState.page ?? 1) || 1);
-  const [pageSize, setPageSize] = useState(25);
+  const [pageSize, setPageSize] = useState(Number(initialState.pageSize ?? 25) || 25);
-  const [sort, setSort] = useState<SortState>({ field: "monthly_sold", direction: "DESC" });
+  const [sort, setSort] = useState<SortState>({
+    field: String(initialState.sortField ?? "monthly_sold"),
+    direction: initialState.sortDirection === "ASC" ? "ASC" : "DESC",
+  });
   const [reanalyzing, setReanalyzing] = useState<Record<string, boolean>>({});
+  const [presetName, setPresetName] = useState("");
+  const [selectedPresetId, setSelectedPresetId] = useState("");
+  const [presets, setPresets] = useState<SavedFilterPreset[]>(() => listFilterPresets(viewKey));
+
+  useEffect(() => {
+    saveViewState(viewKey, {
+      search,
+      activeVerdict,
+      amazonSellerFilter,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    });
+  }, [viewKey, search, activeVerdict, amazonSellerFilter, page, pageSize, sort]);
+
+  function snapshotFilters(): Record<string, unknown> {
+    return {
+      search,
+      activeVerdict,
+      amazonSellerFilter,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    };
+  }
+
+  function applyFilterState(state: Record<string, unknown>) {
+    setSearch(String(state.search ?? ""));
+    setActiveVerdict(String(state.activeVerdict ?? "") as VerdictFilter);
+    setAmazonSellerFilter(state.amazonSellerFilter === "yes" || state.amazonSellerFilter === "no" ? state.amazonSellerFilter : "");
+    setPage(Number(state.page ?? 1) || 1);
+    setPageSize(Number(state.pageSize ?? 25) || 25);
+    setSort({
+      field: String(state.sortField ?? "monthly_sold"),
+      direction: state.sortDirection === "ASC" ? "ASC" : "DESC",
+    });
+  }
+
+  function saveCurrentPreset() {
+    if (!presetName.trim()) return;
+    const saved = saveFilterPreset(viewKey, presetName, snapshotFilters());
+    setPresets(listFilterPresets(viewKey));
+    setSelectedPresetId(saved.id);
+    setPresetName(saved.name);
+  }
+
+  function applySelectedPreset() {
+    if (!selectedPresetId) return;
+    const preset = presets.find((item) => item.id === selectedPresetId);
+    if (!preset) return;
+    applyFilterState(preset.state);
+  }
+
+  function updateSelectedPreset() {
+    if (!selectedPresetId) return;
+    const updated = updateFilterPreset(selectedPresetId, snapshotFilters());
+    if (!updated) return;
+    setPresets(listFilterPresets(viewKey));
+  }
 
   useEffect(() => {
     setActiveVerdict(verdict);
@@ -958,6 +1266,14 @@ function ProductList({ verdict, onBack }: { verdict: VerdictFilter; onBack: () =
             <option value="50">50 / page</option>
             <option value="100">100 / page</option>
           </select>
+          <input value={presetName} onChange={(e) => setPresetName(e.target.value)} placeholder="Preset name" />
+          <select value={selectedPresetId} onChange={(e) => setSelectedPresetId(e.target.value)}>
+            <option value="">Select preset</option>
+            {presets.map((preset) => <option key={preset.id} value={preset.id}>{preset.name}</option>)}
+          </select>
+          <button onClick={saveCurrentPreset}>Save</button>
+          <button disabled={!selectedPresetId} onClick={updateSelectedPreset}>Update</button>
+          <button disabled={!selectedPresetId} onClick={applySelectedPreset}>Apply</button>
         </div>
       </div>
       <div className="card">
@@ -988,7 +1304,7 @@ function ProductList({ verdict, onBack }: { verdict: VerdictFilter; onBack: () =
               ) : items?.items.length ? (
                 items.items.map((item) => (
                   <tr key={`${item.processType}-${item.runId}-${item.asin}-${item.fetched_at}`}>
-                    <td><a href={`/products/${item.asin}`}>{item.asin}</a></td>
+                    <td><button onClick={() => onOpenProduct(item.asin, item.item_id)}>{item.asin}</button></td>
                     <td>{item.verdict ? <span className={verdictBadgeClass(item.verdict)}>{item.verdict}</span> : "-"}</td>
                     <td>{formatNumber(item.monthly_sold)}</td>
                     <td>{formatNumber(item.seller_count)}</td>
@@ -1040,18 +1356,90 @@ function StalkerExplorer({
   onBack: () => void;
   onOpenProducts: () => void;
 }) {
+  const viewKey = "stalker";
+  const initialState = useMemo(() => readViewState(viewKey), []);
   const [results, setResults] = useState<StalkerResultsResponse | null>(null);
   const [loading, setLoading] = useState(false);
   const [purging, setPurging] = useState(false);
-  const [search, setSearch] = useState("");
+  const [search, setSearch] = useState(String(initialState.search ?? ""));
-  const [sellerId, setSellerId] = useState("");
+  const [sellerId, setSellerId] = useState(String(initialState.sellerId ?? ""));
-  const [runId, setRunId] = useState("");
+  const [runId, setRunId] = useState(String(initialState.runId ?? ""));
-  const [minRatingCount, setMinRatingCount] = useState("1");
+  const [minRatingCount, setMinRatingCount] = useState(String(initialState.minRatingCount ?? "1"));
-  const [maxRatingCount, setMaxRatingCount] = useState("30");
+  const [maxRatingCount, setMaxRatingCount] = useState(String(initialState.maxRatingCount ?? "30"));
-  const [page, setPage] = useState(1);
+  const [page, setPage] = useState(Number(initialState.page ?? 1) || 1);
-  const [pageSize, setPageSize] = useState(25);
+  const [pageSize, setPageSize] = useState(Number(initialState.pageSize ?? 25) || 25);
-  const [sort, setSort] = useState<SortState>({ field: "persisted_inventory_asin_count", direction: "DESC" });
+  const [sort, setSort] = useState<SortState>({
+    field: String(initialState.sortField ?? "persisted_inventory_asin_count"),
+    direction: initialState.sortDirection === "ASC" ? "ASC" : "DESC",
+  });
   const [refreshTick, setRefreshTick] = useState(0);
+  const [presetName, setPresetName] = useState("");
+  const [selectedPresetId, setSelectedPresetId] = useState("");
+  const [presets, setPresets] = useState<SavedFilterPreset[]>(() => listFilterPresets(viewKey));
+
+  useEffect(() => {
+    saveViewState(viewKey, {
+      search,
+      sellerId,
+      runId,
+      minRatingCount,
+      maxRatingCount,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    });
+  }, [viewKey, search, sellerId, runId, minRatingCount, maxRatingCount, page, pageSize, sort]);
+
+  function snapshotFilters(): Record<string, unknown> {
+    return {
+      search,
+      sellerId,
+      runId,
+      minRatingCount,
+      maxRatingCount,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+    };
+  }
+
+  function applyFilterState(state: Record<string, unknown>) {
+    setSearch(String(state.search ?? ""));
+    setSellerId(String(state.sellerId ?? ""));
+    setRunId(String(state.runId ?? ""));
+    setMinRatingCount(String(state.minRatingCount ?? "1"));
+    setMaxRatingCount(String(state.maxRatingCount ?? "30"));
+    setPage(Number(state.page ?? 1) || 1);
+    setPageSize(Number(state.pageSize ?? 25) || 25);
+    setSort({
+      field: String(state.sortField ?? "persisted_inventory_asin_count"),
+      direction: state.sortDirection === "ASC" ? "ASC" : "DESC",
+    });
+  }
+
+  function saveCurrentPreset() {
+    if (!presetName.trim()) return;
+    const saved = saveFilterPreset(viewKey, presetName, snapshotFilters());
+    setPresets(listFilterPresets(viewKey));
+    setSelectedPresetId(saved.id);
+    setPresetName(saved.name);
+  }
+
+  function applySelectedPreset() {
+    if (!selectedPresetId) return;
+    const preset = presets.find((item) => item.id === selectedPresetId);
+    if (!preset) return;
+    applyFilterState(preset.state);
+  }
+
+  function updateSelectedPreset() {
+    if (!selectedPresetId) return;
+    const updated = updateFilterPreset(selectedPresetId, snapshotFilters());
+    if (!updated) return;
+    setPresets(listFilterPresets(viewKey));
+  }
 
   useEffect(() => {
     let cancelled = false;
@@ -1144,6 +1532,14 @@ function StalkerExplorer({
             <option value="50">50 / page</option>
             <option value="100">100 / page</option>
           </select>
+          <input value={presetName} onChange={(e) => setPresetName(e.target.value)} placeholder="Preset name" />
+          <select value={selectedPresetId} onChange={(e) => setSelectedPresetId(e.target.value)}>
+            <option value="">Select preset</option>
+            {presets.map((preset) => <option key={preset.id} value={preset.id}>{preset.name}</option>)}
+          </select>
+          <button onClick={saveCurrentPreset}>Save</button>
+          <button disabled={!selectedPresetId} onClick={updateSelectedPreset}>Update</button>
+          <button disabled={!selectedPresetId} onClick={applySelectedPreset}>Apply</button>
         </div>
       </div>
 
@@ -1220,31 +1616,148 @@ function StalkerProductsExplorer({
   onOpenSellers: () => void;
   onOpenProduct: (asin: string, runItemId: number | null) => void;
 }) {
+  const viewKey = "stalker-products";
+  const initialState = useMemo(() => readViewState(viewKey), []);
   const [results, setResults] = useState<StalkerProductsResponse | null>(null);
   const [loading, setLoading] = useState(false);
-  const [search, setSearch] = useState("");
+  const [search, setSearch] = useState(String(initialState.search ?? ""));
-  const [sellerId, setSellerId] = useState("");
+  const [sellerId, setSellerId] = useState(String(initialState.sellerId ?? ""));
-  const [runId, setRunId] = useState("");
+  const [runId, setRunId] = useState(String(initialState.runId ?? ""));
-  const [verdict, setVerdict] = useState("");
+  const [verdict, setVerdict] = useState(String(initialState.verdict ?? ""));
-  const [amazonIsSeller, setAmazonIsSeller] = useState("");
+  const [amazonIsSeller, setAmazonIsSeller] = useState(String(initialState.amazonIsSeller ?? ""));
-  const [minPrice, setMinPrice] = useState("");
+  const [minPrice, setMinPrice] = useState(String(initialState.minPrice ?? ""));
-  const [maxPrice, setMaxPrice] = useState("");
+  const [maxPrice, setMaxPrice] = useState(String(initialState.maxPrice ?? ""));
-  const [minMonthlySold, setMinMonthlySold] = useState("");
+  const [minMonthlySold, setMinMonthlySold] = useState(String(initialState.minMonthlySold ?? ""));
-  const [maxMonthlySold, setMaxMonthlySold] = useState("");
+  const [maxMonthlySold, setMaxMonthlySold] = useState(String(initialState.maxMonthlySold ?? ""));
-  const [minSalesRank, setMinSalesRank] = useState("");
+  const [minSalesRank, setMinSalesRank] = useState(String(initialState.minSalesRank ?? ""));
-  const [maxSalesRank, setMaxSalesRank] = useState("");
+  const [maxSalesRank, setMaxSalesRank] = useState(String(initialState.maxSalesRank ?? ""));
-  const [minSellerCount, setMinSellerCount] = useState("");
+  const [minSellerCount, setMinSellerCount] = useState(String(initialState.minSellerCount ?? ""));
-  const [maxSellerCount, setMaxSellerCount] = useState("");
+  const [maxSellerCount, setMaxSellerCount] = useState(String(initialState.maxSellerCount ?? ""));
-  const [minRatingCount, setMinRatingCount] = useState("");
+  const [minRatingCount, setMinRatingCount] = useState(String(initialState.minRatingCount ?? ""));
-  const [maxRatingCount, setMaxRatingCount] = useState("");
+  const [maxRatingCount, setMaxRatingCount] = useState(String(initialState.maxRatingCount ?? ""));
-  const [minConfidence, setMinConfidence] = useState("");
+  const [minConfidence, setMinConfidence] = useState(String(initialState.minConfidence ?? ""));
-  const [maxConfidence, setMaxConfidence] = useState("");
+  const [maxConfidence, setMaxConfidence] = useState(String(initialState.maxConfidence ?? ""));
-  const [page, setPage] = useState(1);
+  const [page, setPage] = useState(Number(initialState.page ?? 1) || 1);
-  const [pageSize, setPageSize] = useState(50);
+  const [pageSize, setPageSize] = useState(Number(initialState.pageSize ?? 50) || 50);
-  const [sort, setSort] = useState<SortState>({ field: "monthly_sold", direction: "DESC" });
+  const [sort, setSort] = useState<SortState>({
-  const [showSellerIdColumn, setShowSellerIdColumn] = useState(false);
+    field: String(initialState.sortField ?? "monthly_sold"),
-  const [showSellerColumn, setShowSellerColumn] = useState(false);
+    direction: initialState.sortDirection === "ASC" ? "ASC" : "DESC",
-  const [showCategoryColumn, setShowCategoryColumn] = useState(false);
+  });
+  const [showSellerIdColumn, setShowSellerIdColumn] = useState(Boolean(initialState.showSellerIdColumn ?? false));
+  const [showSellerColumn, setShowSellerColumn] = useState(Boolean(initialState.showSellerColumn ?? false));
+  const [showCategoryColumn, setShowCategoryColumn] = useState(Boolean(initialState.showCategoryColumn ?? false));
+  const [presetName, setPresetName] = useState("");
+  const [selectedPresetId, setSelectedPresetId] = useState("");
+  const [presets, setPresets] = useState<SavedFilterPreset[]>(() => listFilterPresets(viewKey));
+
+  useEffect(() => {
+    saveViewState(viewKey, {
+      search,
+      sellerId,
+      runId,
+      verdict,
+      amazonIsSeller,
+      minPrice,
+      maxPrice,
+      minMonthlySold,
+      maxMonthlySold,
+      minSalesRank,
+      maxSalesRank,
+      minSellerCount,
+      maxSellerCount,
+      minRatingCount,
+      maxRatingCount,
+      minConfidence,
+      maxConfidence,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+      showSellerIdColumn,
+      showSellerColumn,
+      showCategoryColumn,
+    });
+  }, [viewKey, search, sellerId, runId, verdict, amazonIsSeller, minPrice, maxPrice, minMonthlySold, maxMonthlySold, minSalesRank, maxSalesRank, minSellerCount, maxSellerCount, minRatingCount, maxRatingCount, minConfidence, maxConfidence, page, pageSize, sort, showSellerIdColumn, showSellerColumn, showCategoryColumn]);
+
+  function snapshotFilters(): Record<string, unknown> {
+    return {
+      search,
+      sellerId,
+      runId,
+      verdict,
+      amazonIsSeller,
+      minPrice,
+      maxPrice,
+      minMonthlySold,
+      maxMonthlySold,
+      minSalesRank,
+      maxSalesRank,
+      minSellerCount,
+      maxSellerCount,
+      minRatingCount,
+      maxRatingCount,
+      minConfidence,
+      maxConfidence,
+      page,
+      pageSize,
+      sortField: sort.field,
+      sortDirection: sort.direction,
+      showSellerIdColumn,
+      showSellerColumn,
+      showCategoryColumn,
+    };
+  }
+
+  function applyFilterState(state: Record<string, unknown>) {
+    setSearch(String(state.search ?? ""));
+    setSellerId(String(state.sellerId ?? ""));
+    setRunId(String(state.runId ?? ""));
+    setVerdict(String(state.verdict ?? ""));
+    setAmazonIsSeller(String(state.amazonIsSeller ?? ""));
+    setMinPrice(String(state.minPrice ?? ""));
+    setMaxPrice(String(state.maxPrice ?? ""));
+    setMinMonthlySold(String(state.minMonthlySold ?? ""));
+    setMaxMonthlySold(String(state.maxMonthlySold ?? ""));
+    setMinSalesRank(String(state.minSalesRank ?? ""));
+    setMaxSalesRank(String(state.maxSalesRank ?? ""));
+    setMinSellerCount(String(state.minSellerCount ?? ""));
+    setMaxSellerCount(String(state.maxSellerCount ?? ""));
+    setMinRatingCount(String(state.minRatingCount ?? ""));
+    setMaxRatingCount(String(state.maxRatingCount ?? ""));
+    setMinConfidence(String(state.minConfidence ?? ""));
+    setMaxConfidence(String(state.maxConfidence ?? ""));
+    setPage(Number(state.page ?? 1) || 1);
+    setPageSize(Number(state.pageSize ?? 50) || 50);
+    setSort({
+      field: String(state.sortField ?? "monthly_sold"),
+      direction: state.sortDirection === "ASC" ? "ASC" : "DESC",
+    });
+    setShowSellerIdColumn(Boolean(state.showSellerIdColumn ?? false));
+    setShowSellerColumn(Boolean(state.showSellerColumn ?? false));
+    setShowCategoryColumn(Boolean(state.showCategoryColumn ?? false));
+  }
+
+  function saveCurrentPreset() {
+    if (!presetName.trim()) return;
+    const saved = saveFilterPreset(viewKey, presetName, snapshotFilters());
+    setPresets(listFilterPresets(viewKey));
+    setSelectedPresetId(saved.id);
+    setPresetName(saved.name);
+  }
+
+  function applySelectedPreset() {
+    if (!selectedPresetId) return;
+    const preset = presets.find((item) => item.id === selectedPresetId);
+    if (!preset) return;
+    applyFilterState(preset.state);
+  }
+
+  function updateSelectedPreset() {
+    if (!selectedPresetId) return;
+    const updated = updateFilterPreset(selectedPresetId, snapshotFilters());
+    if (!updated) return;
+    setPresets(listFilterPresets(viewKey));
+  }
 
   function buildStalkerProductParams(includePaging: boolean): URLSearchParams {
     const params = new URLSearchParams({
@@ -1399,6 +1912,14 @@ function StalkerProductsExplorer({
             <option value="50">50 / page</option>
             <option value="100">100 / page</option>
           </select>
+          <input value={presetName} onChange={(e) => setPresetName(e.target.value)} placeholder="Preset name" />
+          <select value={selectedPresetId} onChange={(e) => setSelectedPresetId(e.target.value)}>
+            <option value="">Select preset</option>
+            {presets.map((preset) => <option key={preset.id} value={preset.id}>{preset.name}</option>)}
+          </select>
+          <button onClick={saveCurrentPreset}>Save</button>
+          <button disabled={!selectedPresetId} onClick={updateSelectedPreset}>Update</button>
+          <button disabled={!selectedPresetId} onClick={applySelectedPreset}>Apply</button>
           <button onClick={resetFilters}>Reset filters</button>
           <a className="button-link" href={exportHref}>Export XLSX</a>
         </div>
@@ -1514,10 +2035,13 @@ function ProductDetails({
   }, [asin]);
 
   async function reanalyze() {
-    if (effectiveRunItemId == null || reanalyzing) return;
+    if (reanalyzing) return;
     setReanalyzing(true);
     try {
-      const res = await fetch(`/api/stalker/products/${effectiveRunItemId}/reanalyze?provider=claude`, { method: "POST" });
+      const endpoint = effectiveRunItemId == null
+        ? `/api/stalker/products/by-asin/${encodeURIComponent(asin)}/reanalyze?provider=claude`
+        : `/api/stalker/products/${effectiveRunItemId}/reanalyze?provider=claude`;
+      const res = await fetch(endpoint, { method: "POST" });
       if (!res.ok) {
         const body = (await res.json().catch(() => null)) as { error?: string } | null;
         window.alert(body?.error ?? "Failed to re-run analysis");
@@ -1530,16 +2054,18 @@ function ProductDetails({
   }
 
   async function discoverDistributors() {
-    if (effectiveRunItemId == null || findingDistributors) return;
+    if (findingDistributors) return;
     setFindingDistributors(true);
     try {
-      const res = await fetch(`/api/stalker/products/${effectiveRunItemId}/distributors`, { method: "POST" });
+      const endpoint = effectiveRunItemId == null
+        ? `/api/stalker/products/by-asin/${encodeURIComponent(asin)}/distributors`
+        : `/api/stalker/products/${effectiveRunItemId}/distributors`;
+      const res = await fetch(endpoint, { method: "POST" });
       if (!res.ok) {
         const body = (await res.json().catch(() => null)) as { error?: string } | null;
         window.alert(body?.error ?? "Failed to find distributors");
       }
     } catch {
-      // network error or timeout — job may have completed on the server anyway
     } finally {
       load();
       setFindingDistributors(false);
@@ -1552,7 +2078,6 @@ function ProductDetails({
       <div className="card">
         <div className="section-header">
           <h2>{data?.product.name ?? asin}</h2>
-          {effectiveRunItemId != null && (
           <div className="button-row">
             <button onClick={reanalyze} disabled={reanalyzing}>
               {reanalyzing ? "Re-running..." : "Re-run analysis"}
@@ -1561,7 +2086,6 @@ function ProductDetails({
               {findingDistributors ? "Finding distributors..." : "Find distributors"}
             </button>
           </div>
-          )}
         </div>
         <div className="meta-grid" style={{ marginTop: 12 }}>
           <div className="meta"><strong>ASIN:</strong> <a href={`https://amazon.com/dp/${asin}`} target="_blank" rel="noreferrer">{asin}</a></div>
@@ -1673,14 +2197,15 @@ function ProductDetails({
   );
 }
 
-type AppRoute =
+type NonProductRoute =
   | { kind: "dashboard" }
   | { kind: "run"; processType: ProcessType; runId: number }
   | { kind: "products"; verdict: VerdictFilter }
-  | { kind: "product"; asin: string; runItemId?: number | null }
   | { kind: "stalker" }
   | { kind: "stalker-products" };
 
+type AppRoute = NonProductRoute | { kind: "product"; asin: string; runItemId?: number | null; backTo?: NonProductRoute };
+
 function parseRoute(pathname: string, search: string): AppRoute {
   const runMatch = pathname.match(/^\/runs\/(\d+)$/);
   if (runMatch) {
@@ -1710,6 +2235,14 @@ function parseRoute(pathname: string, search: string): AppRoute {
   return { kind: "dashboard" };
 }
 
+function routePath(route: NonProductRoute): string {
+  if (route.kind === "run") return `/runs/${route.runId}`;
+  if (route.kind === "products") return route.verdict ? `/products?verdict=${encodeURIComponent(route.verdict)}` : "/products";
+  if (route.kind === "stalker") return "/stalker";
+  if (route.kind === "stalker-products") return "/stalker/products";
+  return "/";
+}
+
 function App() {
   const [route, setRoute] = useState<AppRoute>(() => parseRoute(window.location.pathname, window.location.search));
 
@@ -1746,21 +2279,31 @@ function App() {
     setRoute({ kind: "dashboard" });
   }
 
+  function backFromProduct() {
+    if (route.kind === "product" && route.backTo) {
+      history.pushState({}, "", routePath(route.backTo));
+      setRoute(route.backTo);
+      return;
+    }
+    backToDashboard();
+  }
+
   function openProduct(asin: string, runItemId: number | null) {
     history.pushState({}, "", `/products/${asin}`);
-    setRoute({ kind: "product", asin, runItemId });
+    const backTo: NonProductRoute | undefined = route.kind === "product" ? undefined : route;
+    setRoute({ kind: "product", asin, runItemId, backTo });
   }
 
   if (route.kind === "run") {
-    return <RunDetails processType={route.processType} runId={route.runId} onBack={backToDashboard} />;
+    return <RunDetails processType={route.processType} runId={route.runId} onBack={backToDashboard} onOpenProduct={openProduct} />;
   }
 
   if (route.kind === "products") {
-    return <ProductList verdict={route.verdict} onBack={backToDashboard} />;
+    return <ProductList verdict={route.verdict} onBack={backToDashboard} onOpenProduct={openProduct} />;
   }
 
   if (route.kind === "product") {
-    return <ProductDetails asin={route.asin} runItemId={route.runItemId} onBack={backToDashboard} />;
+    return <ProductDetails asin={route.asin} runItemId={route.runItemId} onBack={backFromProduct} />;
   }
 
   if (route.kind === "stalker") {