Greptile Summary

This PR fixes a repeating IPv6-timeout / polling-stall cycle on Node 22+ hosts with unstable IPv6 routes to api.telegram.org by resolving the undici fetch dispatcher once per TelegramPollingSession lifetime instead of on every bot recreation.

Key changes:

• TelegramPollingSession now calls resolveTelegramFetch() once in its constructor and stores the result in the private #sharedFetch field, so the closure variable stickyIpv4FallbackEnabled (and the lazily-created IPv4 dispatcher) survive across all polling restarts.
• createTelegramBot accepts a new optional resolvedFetch parameter; when provided, it is used directly instead of calling resolveTelegramFetch() again — correctly short-circuiting the "reset sticky state" path.
• monitor.ts forwards account.config.network to TelegramPollingSession so the shared fetch is resolved with the same network settings createTelegramBot would have used, keeping transport decisions consistent.
• Non-polling callers (webhook mode, one-shot scripts) are entirely unaffected — they never pass resolvedFetch, so their code path is unchanged.

The implementation is minimal and well-scoped. The abort-signal wrapper and network-error tagging wrapper in bot.ts are correctly layered on top of whichever fetch is chosen, so the sticky dispatcher state in the shared fetch is preserved while per-request abort signals still work as expected.

Confidence Score: 5/5

• This PR is safe to merge — the change is narrow, logically sound, and has no impact on non-polling code paths.
• The fix directly models the correct lifetime for the fetch closure: one fetch instance per polling session rather than one per bot recreation. No existing logic is removed; resolvedFetch is purely additive and the existing ?? fallback guarantees backward compatibility for every non-polling caller. The only external-facing change in monitor.ts is passing a value that was already available on the account config, making the two resolution sites consistent. No edge cases were found that would alter existing behavior.
• No files require special attention.

_{Last reviewed commit: 501e27c}