feat: implement SQLite persistent storage for analysis results

- Implemented database initialization and connection management in `database.ts` using Bun's SQLite.
- Created `runs` and `results` tables to track historical analysis metadata and detailed product performance.
- Updated `writer.ts` to persist analysis results to the database within a transaction, replacing the previous CSV output logic.
- Updated README and `.gitignore` to reflect the new persistent storage capability.

src/index.ts

@@ -3,7 +3,10 @@ import { fetchKeepaDataBatch } from "./keepa.ts";
 import { fetchSellabilityBatch, fetchSpApiPricingAndFees } from "./sp-api.ts";
 import { connectCache, getCache, setCache, disconnectCache } from "./cache.ts";
 import { analyzeProducts } from "./llm.ts";
-import { printResults, writeResultsCsv } from "./writer.ts";
+import { printResults, writeResultsToDb } from "./writer.ts";
+import { initDb, closeDb } from "./database.ts";
+
+const DB_PATH = "./results.db";
 import type {
   EnrichedProduct,
   AnalysisResult,
@@ -35,6 +38,10 @@ async function main() {
   console.log("Connecting to Redis...");
   await connectCache();
 
+  // Initialize SQLite DB
+  console.log("Initializing SQLite database...");
+  initDb(DB_PATH);
+
   // Phase 1: Read input file
   console.log(`\nReading ${inputFile}...`);
   const products = readProducts(inputFile);
@@ -279,11 +286,10 @@ async function main() {
 
   printResults(allResults);
 
-  if (outputFile) {
-    writeResultsCsv(allResults, outputFile);
-  }
+  writeResultsToDb(allResults, DB_PATH, inputFile, outputFile);
 
   await disconnectCache();
+  closeDb();
 }
 
 main().catch((err) => {