chore: remove unused backfill scripts (SIT-302)

package.json

@@ -37,8 +37,6 @@
   "scripts": {
     "build": "tsc",
     "dev": "tsx watch src/index.ts",
-    "backfill:bot-flags": "tsx src/scripts/backfill-bot-flags.ts",
-    "backfill:attribution": "tsx src/scripts/backfill-attribution.ts",
     "migrate": "tsx src/scripts/migrate.ts",
     "test": "vitest run",
     "test:watch": "vitest",

src/lib/database.ts

@@ -396,7 +396,7 @@ export async function initializeDatabase(options: DatabaseOptions = {}) {
     // Bot classification columns on click_events (SIT-298). Classified at
     // ingestion (see lib/bot-detection.ts) and persisted so every consumer reads
     // one consistent flag; analytics excludes is_bot rows. Backward compatible:
-    // legacy rows default to is_bot=false until the one-time backfill runs.
+    // legacy rows default to is_bot=false and age out of the retention window.
     await client.query(`
       DO $$
       BEGIN