feat: Refactor settings UI and fix commission fee recording

Settings improvements:
- Reorganize config groups with logical ordering (server, auth, ai, trading, etc.)
- Add description/tooltip for each config item with question mark icon
- Add icon to each group header
- Support i18n for descriptions (zh-CN, zh-TW, en-US)
- Move order execution config (ORDER_MODE, MAKER_WAIT_SEC, MAKER_OFFSET_BPS) to env

Commission fee fixes:
- Fix fee extraction in exchange clients: Bybit, Coinbase, Kraken, Gate, Kucoin, Bitfinex
- Properly accumulate and record commission fees in pending_order_worker
- Add fee/fee_ccy fields to wait_for_fill returns

Frontend updates:
- Remove order_mode config from trading-assistant frontend (now uses env config)
- Add sorted schema display by order field
- Add tooltip with description on hover

backend_api_python/env.example

@@ -34,6 +34,22 @@ ENABLE_PENDING_ORDER_WORKER=true
 # Reclaim orders stuck in status=processing after worker crashes (seconds).
 PENDING_ORDER_STALE_SEC=90
 
+# =========================
+# Live trading order execution settings
+# =========================
+# Order execution mode:
+#   - "maker": Limit order first, then market order for remaining (default, lower fees)
+#   - "market": Market order only (immediate execution, higher fees)
+ORDER_MODE=maker
+
+# How long to wait for limit order to fill before switching to market order (seconds)
+MAKER_WAIT_SEC=10
+
+# Price offset for limit orders in basis points (1 bps = 0.01%)
+# Buy orders: price = market_price * (1 - offset)
+# Sell orders: price = market_price * (1 + offset)
+MAKER_OFFSET_BPS=2
+
 # =========================
 # Strategy signal notifications (optional)
 # =========================