refactor: remove mock trading functionality from backend and frontend

Removes all mock price simulation features:
- Delete MockPriceManager from backend/data/
- Remove mock_mode, enable_mock, is_mock_mode flags from services
- Remove mock CLI options and config
- Remove mock mode UI components and state from frontend
- Update tests to remove mock references

Now system supports only live and backtest modes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/services/market.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 """
 Market Data Service
-Supports live, mock, and backtest modes
+Supports live and backtest modes
 """
 import asyncio
 import logging
@@ -36,7 +36,6 @@ class MarketService:
         self,
         tickers: List[str],
         poll_interval: int = 10,
-        mock_mode: bool = False,
         backtest_mode: bool = False,
         api_key: Optional[str] = None,
         backtest_start_date: Optional[str] = None,
@@ -44,7 +43,6 @@ class MarketService:
     ):
         self.tickers = [normalize_symbol(ticker) for ticker in tickers]
         self.poll_interval = poll_interval
-        self.mock_mode = mock_mode
         self.backtest_mode = backtest_mode
         self.api_key = api_key
         self.backtest_start_date = backtest_start_date
@@ -69,8 +67,6 @@ class MarketService:
         """Return the active live quote provider for UI/debugging."""
         if self.backtest_mode:
             return "backtest"
-        if self.mock_mode:
-            return "mock"
         if self._price_manager and hasattr(self._price_manager, "provider"):
             provider = getattr(self._price_manager, "provider", None)
             if isinstance(provider, str) and provider.strip():
@@ -81,8 +77,6 @@ class MarketService:
     def mode_name(self) -> str:
         if self.backtest_mode:
             return "BACKTEST"
-        elif self.mock_mode:
-            return "MOCK"
         return "LIVE"
 
     async def start(self, broadcast_func: Callable):
@@ -96,8 +90,6 @@ class MarketService:
 
         if self.backtest_mode:
             self._start_backtest_mode()
-        elif self.mock_mode:
-            self._start_mock_mode()
         else:
             self._start_real_mode()
 
@@ -125,20 +117,6 @@ class MarketService:
 
         return callback
 
-    def _start_mock_mode(self):
-        from backend.data.mock_price_manager import MockPriceManager
-
-        self._price_manager = MockPriceManager(
-            poll_interval=self.poll_interval,
-            volatility=0.5,
-        )
-        self._price_manager.add_price_callback(self._make_price_callback())
-        self._price_manager.subscribe(
-            self.tickers,
-            base_prices={t: 100.0 for t in self.tickers},
-        )
-        self._price_manager.start()
-
     def _start_real_mode(self):
         from backend.data.polling_price_manager import PollingPriceManager
 
@@ -262,13 +240,7 @@ class MarketService:
             if removed:
                 self._price_manager.unsubscribe(removed)
             if added:
-                if self.mock_mode:
-                    self._price_manager.subscribe(
-                        added,
-                        base_prices={ticker: 100.0 for ticker in added},
-                    )
-                else:
-                    self._price_manager.subscribe(added)
+                self._price_manager.subscribe(added)
 
             if self.backtest_mode and self._current_date:
                 self._price_manager.set_date(self._current_date)