Multi-strategy UI

Adds a "Strategies (multi)" panel: add/remove strategy rows (strategy, symbol,
timeframe, per-strategy params and weight), start all, stop all and kill all,
plus a per-strategy status table (allocation, equity, P&L, halted). Polls
/api/bot/status alongside the existing status. Includes component tests.

README.md

@@ -144,6 +144,15 @@ injects it on the handshake). If `API_TOKEN` is unset, `/api/ws` is as open as
 the rest of `/api`, which is fine for a trusted/private deployment but is the
 reason to set a token if the host is exposed.
 
+## Multi-strategy
+
+The **Strategies (multi)** panel runs several strategies at once, each with its
+own capital slice. Set a **weight** per strategy; weights are normalised across
+the run (`[1, 3]` gives 25% / 75%) and each strategy starts with
+`starting_balance × allocation` as its own cash, so one strategy's losses cannot
+drain another's. Risk limits apply per strategy, and **Kill all** flattens and
+halts every one.
+
 ## Risk controls
 
 The engine enforces limits on every tick and **halts + flattens** when one trips:
@@ -182,6 +191,8 @@ Bundled strategies: `sma_cross`, `ema_cross`, `macd_trend`,
 | `GET` | `/api/status` | Bot status, equity, P&L |
 | `GET` | `/api/strategies` | Available strategies + parameter specs |
 | `POST` | `/api/bot/start` | Start a strategy |
+| `POST` | `/api/bot/start-many` | Start several strategies with per-strategy allocations |
+| `GET` | `/api/bot/status` | Per-strategy status for a multi-strategy run |
 | `POST` | `/api/bot/stop` | Stop the bot |
 | `POST` | `/api/bot/kill` | Kill switch: flatten + halt |
 | `POST` | `/api/backtest` | Backtest a strategy on historical candles |