Feature: /pause and /resume slash commands

[Rustam-Z]

Summary

Add two owner-only slash commands to the harness for temporary message muting without taking the bot down.

• /pause — drop all inbound Telegram messages until resumed. The dispatcher continues running, the CC session stays warm, but no <msg> envelopes are forwarded to the model. Reminders / cron / self-reflection skills still fire if scheduled.
• /resume — re-enable message forwarding. Messages received while paused are dropped, not queued.

Why

• Operator needs a way to stop the bot from replying without restarting it (which costs warm context per Encoded prompt injections (base64, Morse) crash Claude Code sessions #39).
• Useful while testing, debugging, deploying a config change, or when a chat starts flooding the bot.
• Currently the only options are /kill (which is broken per /kill slash command silently does nothing #40 and would wipe context anyway) or host-level intervention.

Behavior details

• Both commands are owner-only, intercepted by the harness, never reach the LLM.
• /pause acknowledges in the chat where it's invoked: e.g. "⏸ paused — messages dropped until /resume".
• /resume acknowledges: e.g. "▶ resumed".
• While paused, the harness silently drops inbound user messages from all chats (no "the bot is paused" auto-reply — that would just spam). Owner messages in the owner DM are also dropped, so the pause state is shown in /health to make it discoverable.
• State persists across container restarts? Suggestion: no — restart implies a fresh start and operator intent is usually to resume. State lives in memory only.

Suggested implementation

• New paused: bool flag on the dispatcher.
• Slash-command handler flips the flag, replies, returns early.
• Inbound message middleware checks the flag before persistence + forward; if paused, drop (don't even write to the messages table — keeps the DB clean for Encoded prompt injections (base64, Morse) crash Claude Code sessions #39's CI corpus work).
• /health reports the flag.

Severity

Feature request, low urgency. But pairs naturally with the /kill fix (#40) and the auto-restart work (#39) — together they round out the ops surface for managing a live bot from Telegram.