refactor: migrate messageStore to drizzle-orm

- Replace all raw SQL queries in messageStore.ts with Drizzle ORM queries
- Remove DatabaseAdapter dependency from messageStore functions
- Update all function signatures to be async and remove db parameter
- Functions now use getDatabase() internally for database access
- Update all call sites in messageCapture.ts, attachmentUploader.ts, aiAnalyzer.ts, webserver.ts, and index.ts
- All functions remain backward compatible in behavior
- TypeScript typecheck passes with no errors
- All tests pass (11 passed)

src/index.ts

@@ -78,7 +78,7 @@ async function initializeApp() {
   client.on("ready", async () => {
     logger.info({ user: client.user?.tag }, "Bot logged in");
     registerMessageCapture(client, db!);
-    startPendingAIAnalysisWorker(db!);
+    startPendingAIAnalysisWorker();
     syncBacklogMessages(client, db!).catch((error) => {
       logger.warn({ error }, "Backlog sync failed");
     });