Observability: Prometheus metrics, log panel, runbook

- GET /api/metrics renders Prometheus text (equity, P&L, per-strategy
  equity/pnl/allocation/halted, info) with no client library.
- In-memory ring log handler (app/logs.py) exposed at GET /api/logs and a
  dashboard "Server logs" panel; Runtime mirrors bot events into the logger.
- docs/runbook.md covers deploys, the kill switch, resetting paper state and
  going live. Adds tests for metrics rendering and the log ring.

docs/runbook.md

@@ -0,0 +1,59 @@
+# Operations runbook
+
+Practical steps for running the deployed bot. Host paths are examples — adjust
+to the deploy host.
+
+## Find the stack
+
+```bash
+docker compose ps
+docker compose logs --tail=200 backend
+docker compose logs -f frontend
+```
+
+The backend exposes `GET /api/metrics` (Prometheus text format) for the existing
+Prometheus/Grafana stack; scrape it alongside the other services. Useful series:
+`crypto_running`, `crypto_equity`, `crypto_total_pnl`, `crypto_open_positions`,
+`crypto_strategy_equity`, `crypto_strategy_pnl`, `crypto_strategy_halted`,
+`crypto_info`.
+
+## Stop / kill trading
+
+- **Dashboard:** the **Kill all** button (or Stop all) flattens and halts.
+- **API:** `curl -X POST -H "X-API-Token: $TOKEN" https://<host>/api/bot/kill`
+- **Hard stop:** `docker compose stop backend` stops the process entirely. It
+  does **not** close open positions — use the API kill first if you care.
+
+## Something is wrong
+
+1. `docker compose ps` — is the service `healthy`?
+2. `docker compose logs --tail=200 backend` — look for `error`/`Traceback`.
+3. In the dashboard, open **Server logs** (shows the in-memory ring of recent
+   log lines) and **Activity** (trades, halts, errors).
+4. `curl https://<host>/api/live-check` — if live is blocked, the reasons are
+   listed.
+
+## A deploy went out but the UI looks stale
+
+The deploy job fails if the frontend container's build stamp does not match the
+commit; if you see stale UI and the job passed, hard-refresh or open
+incognito. The footer shows `client` vs `server` versions — they must match.
+
+## Reset paper state
+
+```bash
+docker compose stop backend
+# remove the SQLite file on the host mount
+rm -f <CRYPTO_DATA_DIR>/trader.db
+docker compose start backend
+```
+
+## Going live (do this deliberately)
+
+1. Rehearse the kill switch in paper mode.
+2. Set `MAX_DAILY_LOSS`, `MAX_DRAWDOWN_PCT` and/or `MAX_TRADES_PER_DAY`, and
+   `MAX_POSITION_PCT < 1.0`.
+3. Set `MIN_LIVE_BALANCE` and add exchange credentials.
+4. Set `LIVE_CONFIRMATION="I UNDERSTAND THE RISK"`.
+5. Deploy, confirm `/api/live-check` returns `ok: true`, then start with a
+   small balance and watch it.