Fix worker getting stuck during sync: add timeouts, stuck detection, and safety limits

- Add invokeWithTimeout wrapper for TDLib API calls (2min timeout per call)
- Add stuck detection to getChannelMessages: break if from_message_id doesn't advance
- Add stuck detection to getTopicMessages: same protection for topic scanning
- Add stuck detection to getForumTopicList: break if pagination offsets don't advance
- Add max page limit (5000) to all scanning loops to prevent infinite pagination
- Add mutex wait timeout (30min) to prevent indefinite blocking when holder hangs
- Add cycle timeout (4h default, configurable via WORKER_CYCLE_TIMEOUT_MINUTES)
- Fix end-of-page detection to use actual limit value instead of hardcoded 100

Co-authored-by: xCyanGrizzly <53275238+xCyanGrizzly@users.noreply.github.com>

worker/dist/archive/hash.d.ts

@@ -0,0 +1,6 @@
+/**
+ * Compute SHA-256 hash of one or more files by streaming them in order.
+ * Memory usage: O(1) — reads in 64KB chunks regardless of total size.
+ * For multipart archives, pass all parts sorted by part number.
+ */
+export declare function hashParts(filePaths: string[]): Promise<string>;