feat(telegram): add "skip & disable topic" on the live worker panel

Track the forum topic currently being processed on IngestionRun
(currentTopicId + currentAccountChannelMapId; additive migration) and
expose it on the live status. processArchiveSets gains an optional
shouldStop callback polled before each archive set; the forum branch
passes a live isTopicFetchEnabled check, so disabling a topic mid-run
lets the in-flight file finish, then skips the rest of that topic.

A new disableActiveTopic server action sets the topic's fetchEnabled
false (upsert), and the worker status panel shows a "Skip & disable
this topic" button while a topic is being processed. Future runs skip
the topic via the existing live per-topic read.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

prisma/migrations/20260622120000_add_run_current_topic/migration.sql

@@ -0,0 +1,6 @@
+-- AlterTable: track the forum topic currently being processed on the live run
+-- so the worker status panel can offer a "skip & disable topic" action.
+-- Additive, nullable — no data change for existing rows.
+ALTER TABLE "ingestion_runs"
+  ADD COLUMN "currentTopicId" BIGINT,
+  ADD COLUMN "currentAccountChannelMapId" TEXT;