fix(worker): prune TDLib's unbounded local file cache after each run

TDLib keeps a permanent local copy of every file it downloads or
uploads (via inputFileLocal) with no automatic cleanup. Across the two
worker accounts this had grown to ~270GB, filling the host disk to 91%
and triggering a cascading disk-full failure in the bot's TDLib
session on 2026-08-05. Call optimizeStorage after every ingestion run
to clear it; a 5-minute immunity_delay protects files an in-flight
operation might still reference.

worker/src/worker.ts

@@ -42,7 +42,7 @@ import {
   isTopicFetchEnabled,
 } from "./db/queries.js";
 import type { ActivityUpdate } from "./db/queries.js";
-import { createTdlibClient, closeTdlibClient } from "./tdlib/client.js";
+import { createTdlibClient, closeTdlibClient, optimizeTdlibStorage } from "./tdlib/client.js";
 import {
   getAccountChats,
   joinChatByInviteLink,
@@ -1203,6 +1203,7 @@ export async function runWorkerForAccount(
       accountLog.info({ counters }, "Ingestion run completed");
     } finally {
       await throttled.flush();
+      await optimizeTdlibStorage(client, account.id);
       await closeTdlibClient(client);
     }
   } catch (err) {