fix(telegram): increase dedup TTL and log offset confirmation failures

The Telegram update dedup cache had a 5-minute TTL which could expire
during extended polling restart cycles (backoff, stall detection, etc.),
allowing already-processed messages to be re-delivered.

- Increase dedup cache TTL from 5 to 30 minutes to survive all realistic
  restart windows
- Increase max cache size from 2000 to 5000 to match the longer TTL
- Log a warning when confirmPersistedOffset fails so operators can
  diagnose duplicate-message issues

Closes #46674

extensions/telegram/src/bot-updates.ts

@@ -3,8 +3,11 @@ import { createDedupeCache } from "openclaw/plugin-sdk/infra-runtime";
 import type { TelegramContext } from "./bot/types.js";
 
 const MEDIA_GROUP_TIMEOUT_MS = 500;
-const RECENT_TELEGRAM_UPDATE_TTL_MS = 5 * 60_000;
-const RECENT_TELEGRAM_UPDATE_MAX = 2000;
+// Dedup cache TTL must survive the longest possible polling restart cycle
+// (backoff up to 30s × multiple attempts + 90s stall threshold + 15s grace).
+// 30 minutes keeps entries alive well past any realistic restart window (#46674).
+const RECENT_TELEGRAM_UPDATE_TTL_MS = 30 * 60_000;
+const RECENT_TELEGRAM_UPDATE_MAX = 5000;
 
 export type MediaGroupEntry = {
   messages: Array<{

extensions/telegram/src/polling-session.ts

@@ -177,8 +177,12 @@ export class TelegramPollingSession {
     }
     try {
       await bot.api.getUpdates({ offset: lastUpdateId + 1, limit: 1, timeout: 0 });
-    } catch {
+    } catch (err) {
       // Non-fatal: runner middleware still skips duplicates via shouldSkipUpdate.
+      // Log a warning so operators can diagnose duplicate-message issues (#46674).
+      this.opts.log(
+        `[telegram] failed to confirm persisted offset ${lastUpdateId}: ${formatErrorMessage(err)}; relying on dedup cache.`,
+      );
     }
   }