feat: transition bestseller analysis storage to SQLite and add category blacklist

- Replaces Excel output with structured database tables for tracking category analysis runs and product results.
- Implements a blacklist to exclude specific category IDs from the bestseller pipeline.
- Adds unit tests for category processing and enhances logging with levels and timestamps.
- Introduces foreign key enforcement and updated schema definitions in the database module.

src/database.ts

@@ -1,4 +1,5 @@
 import { Database } from "bun:sqlite";
+export { Database } from "bun:sqlite";
 
 let db: Database | null = null;
 
@@ -6,6 +7,7 @@ export function getDb(dbPath: string): Database {
   if (!db) {
     db = new Database(dbPath);
     db.run("PRAGMA journal_mode = WAL;"); // Enable WAL mode for better performance
+    db.run("PRAGMA foreign_keys = ON;"); // Enforce foreign key constraints
   }
   return db;
 }
@@ -50,20 +52,6 @@ export function initDb(dbPath: string): void {
       monthly_sold INTEGER,
       rank_drops_30d INTEGER,
       rank_drops_90d INTEGER,
-      fba_net_sheet REAL,
-      gross_profit_dollar REAL,
-      gross_profit_pct REAL,
-      net_profit_sheet REAL,
-      roi_sheet REAL,
-      moq INTEGER,
-      moq_cost REAL,
-      qty_available INTEGER,
-      supplier TEXT,
-      source_url TEXT,
-      asin_link TEXT,
-      promo_coupon_code TEXT,
-      notes TEXT,
-      lead_date TEXT,
       fba_fee REAL,
       fbm_fee REAL,
       referral_percent REAL,
@@ -77,4 +65,50 @@ export function initDb(dbPath: string): void {
       FOREIGN KEY (run_id) REFERENCES runs(id)
     );
   `);
+  database.run(`
+    CREATE TABLE IF NOT EXISTS category_analysis_runs (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      category_id INTEGER NOT NULL,
+      category_label TEXT NOT NULL,
+      run_timestamp TEXT NOT NULL,
+      top_asins_checked INTEGER NOT NULL,
+      available_asins INTEGER NOT NULL,
+      fba_count INTEGER NOT NULL,
+      fbm_count INTEGER NOT NULL,
+      skip_count INTEGER NOT NULL,
+      status TEXT NOT NULL,
+      error_message TEXT
+    );
+  `);
+  database.run(`
+    CREATE TABLE IF NOT EXISTS product_analysis_results (
+      asin TEXT PRIMARY KEY,
+      run_id INTEGER NOT NULL,
+      name TEXT NOT NULL,
+      brand TEXT,
+      category TEXT,
+      unit_cost REAL,
+      current_price REAL,
+      avg_price_90d REAL,
+      avg_price_90d_sheet REAL,
+      selling_price_sheet REAL,
+      sales_rank INTEGER,
+      sales_rank_avg_90d INTEGER,
+      seller_count INTEGER,
+      monthly_sold INTEGER,
+      rank_drops_30d INTEGER,
+      rank_drops_90d INTEGER,
+      fba_fee REAL,
+      fbm_fee REAL,
+      referral_percent REAL,
+      can_sell TEXT,
+      sellability_status TEXT,
+      sellability_reason TEXT,
+      verdict TEXT NOT NULL,
+      confidence REAL NOT NULL,
+      reasoning TEXT,
+      fetched_at TEXT NOT NULL,
+      FOREIGN KEY (run_id) REFERENCES category_analysis_runs(id)
+    );
+  `);
 }