Deduplicate repeated Telegram webhook updates

[onmax]

Summary

Telegram retries webhook deliveries after non-2xx responses, and its update_id field is explicitly intended for ignoring repeated updates. The Telegram adapter previously routed every webhook delivery independently.

This change atomically claims each integer update_id through the configured StateAdapter before routing the update. Repeated deliveries return 200 without reaching bot handlers, while state failures return 503 without dispatching so Telegram can retry. Updates without an integer update_id keep their existing behavior, and polling remains unchanged.

Claims expire after 24 hours because Telegram retains incoming updates for no longer than 24 hours. This is a bounded retention choice, not a documented retry timeout. Cross-instance deduplication requires shared durable state; in-memory state only protects one process. The change provides webhook-delivery idempotency, not end-to-end exactly-once handler completion.

Telegram contract: Update and setWebhook.

Test plan

• pnpm --filter @chat-adapter/telegram test
• pnpm --filter @chat-adapter/telegram typecheck
• pnpm check
• pnpm konsistent
• TURBO_CONCURRENCY=1 pnpm validate

Regression coverage verifies sequential and concurrent repeated deliveries, distinct update IDs, missing update IDs, duplicate 200 responses, and state-failure retry behavior. GitHub CI also passes on Node 22 and Node 24.

Checklist

• All commits are signed and verified
• All commits are signed off for the DCO (git commit -s)
• pnpm validate passes
• Changeset added (or N/A — see CONTRIBUTING.md)
• Documentation updated (or N/A)

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