feat(gateway): wire clarify tool with inline keyboard buttons on Telegram (#24199)

The clarify tool returned 'not available in this execution context' for
every gateway-mode agent because gateway/run.py never passed
clarify_callback into the AIAgent constructor. Schema actively encouraged
calling it; users never saw the question.

Changes:

- tools/clarify_gateway.py — new event-based primitive mirroring
  tools/approval.py: register/wait_for_response/resolve_gateway_clarify
  with per-session FIFO, threading.Event blocking with 1s heartbeat
  slices (so the inactivity watchdog keeps ticking), and
  clear_session for boundary cleanup.

- gateway/platforms/base.py — abstract send_clarify with a numbered-text
  fallback so every adapter (Discord, Slack, WhatsApp, Signal, Matrix,
  etc.) gets a working clarify out of the box. Plus an active-session
  bypass: when the agent is blocked on a text-awaiting clarify, the next
  non-command message routes inline to the runner's intercept instead
  of being queued + triggering an interrupt. Same shape as the /approve
  deadlock fix from PR #4926.

- gateway/platforms/telegram.py — concrete send_clarify renders one
  inline button per choice plus '✏️ Other (type answer)'. cl: callback
  handler resolves numeric choices immediately, flips to text-capture
  mode for Other, with the same authorization guards as exec/slash
  approvals.

- gateway/run.py — clarify_callback wired at the cached-agent per-turn
  callback assignment site (only the user-facing agent path; cron and
  hygiene-compress agents have no human attached). Bridges sync→async
  via run_coroutine_threadsafe, blocks with the configured timeout, and
  returns a '[user did not respond within Xm]' sentinel on timeout so
  the agent adapts rather than pinning the running-agent guard. Text-
  intercept added to _handle_message before slash-confirm intercept
  (skipping slash commands). clear_session called in the run's finally
  to cancel any orphan entries.

- hermes_cli/config.py — agent.clarify_timeout default 600s.

- website/docs/user-guide/messaging/telegram.md — Interactive Prompts
  section.

Tests:

- tests/tools/test_clarify_gateway.py (14 tests) — full primitive
  coverage: button resolve, open-ended auto-await, Other flip, timeout
  None, unknown-id idempotency, clear_session cancellation, FIFO
  ordering, register/unregister notify, config default.

- tests/gateway/test_telegram_clarify_buttons.py (12 tests) — render
  paths (multi-choice/open-ended/long-label/HTML-escape/not-connected),
  callback dispatch (numeric resolve/Other flip/already-resolved/
  unauthorized/invalid-token), and base-adapter text fallback.

Out of scope: bot-to-bot, guest mode, checklists, poll media, live
photos. Closes #24191.

website/docs/user-guide/messaging/telegram.md

@@ -907,6 +907,19 @@ When the agent tries to run a potentially dangerous command, it asks you for app
 
 Reply "yes"/"y" to approve or "no"/"n" to deny.
 
+## Interactive Prompts (clarify)
+
+When the agent calls the `clarify` tool — to ask which approach you prefer, get post-task feedback, or check before a non-trivial decision — Telegram renders the question with **inline keyboard buttons**:
+
+> ❓ Which framework should I use for the dashboard?
+>
+> [1. Next.js] [2. Remix] [3. Astro]
+> [✏️ Other (type answer)]
+
+Tap a button to answer, or tap **Other** to type a free-form response (the next message you send becomes the answer). Open-ended `clarify` calls (no preset choices) skip the buttons and just capture your next message.
+
+Configure the response timeout via `agent.clarify_timeout` in `~/.hermes/config.yaml` (default `600` seconds). If you don't respond within the timeout, the agent unblocks with a sentinel message and adapts rather than hanging.
+
 ## Security
 
 :::warning