Bitcoin favicon, more strategies, default timeframe 5m

- Add an SVG Bitcoin favicon and link it in index.html.
- New indicators: macd() and roc().
- Five new strategies: macd_trend, bollinger_reversion, donchian_breakout,
  ema_cross, momentum (plus the existing sma_cross, rsi_reversion).
- Default TIMEFRAME is now 5m (config, .env.example, compose, workflow, UI).

README.md

@@ -101,7 +101,7 @@ All settings are environment variables (see `.env.example`):
 | `MODE` | `paper` | `paper` or `live` |
 | `EXCHANGE` | `binance` | Market data / execution venue |
 | `SYMBOL` | `BTC/USDT` | Default trading pair |
-| `TIMEFRAME` | `1m` | Candle interval |
+| `TIMEFRAME` | `5m` | Candle interval |
 | `POLL_INTERVAL` | `5` | Seconds between ticks |
 | `STARTING_BALANCE` | `10000` | Paper account size |
 | `FEE_BPS` / `SLIPPAGE_BPS` | `10` / `5` | Paper fill model |
@@ -159,8 +159,10 @@ from `https://api.telegram.org/bot<token>/getUpdates`.
 
 Drop a file in `backend/app/engine/strategies/` — it is auto-discovered and
 appears in the UI immediately. See **[AGENTS.md](AGENTS.md)** for the full
-template and the `StrategyContext` API. Two examples ship in the repo:
-`sma_cross` and `rsi_reversion`.
+template and the `StrategyContext` API.
+
+Bundled strategies: `sma_cross`, `ema_cross`, `macd_trend`,
+`bollinger_reversion`, `donchian_breakout`, `momentum`, `rsi_reversion`.
 
 ## API