feat: add preview management, channel controls, invite polish, and recovery

- Auto-extract preview images from ZIP/RAR/7z archives during ingestion
- Upload custom preview images via package drawer
- Select preview from archive contents with on-demand extraction UI
- Manually add Telegram channels by t.me link, username, or invite link
- Invite code UX: bulk create, copy link, usage tracking, delete confirm
- Incomplete upload recovery: verify dest messages on worker startup
- Rebuild package DB by scanning destination channel with live progress

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

worker/src/index.ts

@@ -3,6 +3,7 @@ import { config } from "./util/config.js";
 import { logger } from "./util/logger.js";
 import { markStaleRunsAsFailed } from "./db/queries.js";
 import { cleanupTempDir } from "./worker.js";
+import { recoverIncompleteUploads } from "./recovery.js";
 import { startScheduler, stopScheduler } from "./scheduler.js";
 import { startFetchListener, stopFetchListener } from "./fetch-listener.js";
 import { db, pool } from "./db/client.js";
@@ -26,6 +27,10 @@ async function main(): Promise<void> {
   await cleanupTempDir();
   await markStaleRunsAsFailed();
 
+  // Verify destination messages exist for all "uploaded" packages.
+  // Resets any packages whose dest message is missing so they get re-processed.
+  await recoverIncompleteUploads();
+
   // Start the fetch listener (pg_notify for on-demand channel fetching)
   await startFetchListener();