test: add integrations, cache, cron, and telemetry tests

- New integrations.test.ts: 13 tests covering CRUD, token generation,
  token lookup, regeneration, and multi-user isolation
- New cache.test.ts: 3 tests for purgeMetadataCache (shell title
  deletion, fully-fetched title preservation, empty case)
- New cron.test.ts: 5 tests for cron run lifecycle (start, complete,
  fail with Error and string)
- New telemetry.test.ts: 7 tests for isTelemetryEnabled toggle and
  performTelemetryReport (disabled skip, enabled send, 24h interval
  throttle, interval expiry, fetch failure resilience)

345 → 386 tests passing across 27 files

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/db/.oxlintrc.json

@@ -1,5 +1,10 @@
 {
   "$schema": "../../node_modules/oxlint/configuration_schema.json",
   "extends": ["../../.oxlintrc.json"],
+  "jsPlugins": ["eslint-plugin-drizzle"],
+  "rules": {
+    "drizzle/enforce-delete-with-where": ["error", { "drizzleObjectName": ["db", "tx"] }],
+    "drizzle/enforce-update-with-where": ["error", { "drizzleObjectName": ["db", "tx"] }]
+  },
   "ignorePatterns": ["node_modules", "dist", "build", "drizzle"]
 }