Replace the runner-introspection trick in #32998 with an explicit
`set_topic_recovery_fn` setter on `BasePlatformAdapter`. The gateway
runner installs it once at adapter init; the adapter calls
`_apply_topic_recovery(event)` before any session keying.
Also apply the hook in `BasePlatformAdapter.handle_message` so the
running-agent guard and pending-message queue key off the recovered
thread_id too — not just the text-batch coalescence.
Net change vs #32998 alone: -2 files of indirection (no
`_message_handler.__self__` peek, no separate `_normalize_text_batch_source`),
+1 generic mechanism (other adapters can install their own hook later).
When a user sends a long message, Telegram clients split it into
multiple updates that arrive within milliseconds of each other.
Previously each chunk was dispatched independently — the first would
start the agent, and subsequent chunks would interrupt or queue as
separate turns, causing the agent to only see part of the message.
Add text message batching to TelegramAdapter following the same pattern
as the existing photo burst batching:
- _enqueue_text_event() buffers text by session key, concatenating
chunks that arrive in rapid succession
- _flush_text_batch() dispatches the combined message after a 0.6s
quiet period (configurable via HERMES_TELEGRAM_TEXT_BATCH_DELAY_SECONDS)
- Timer resets on each new chunk, so all parts of a split arrive
before the batch is dispatched
Reported by NulledVector on Discord.
