feat: reset endpoint now liquidates Alpaca positions and cancels orders

- Added cancel_all_orders() and close_all_positions() to AlpacaBrokerAdapter
- Reset endpoint creates a temporary adapter to call Alpaca DELETE /v2/orders
  and DELETE /v2/positions before clearing DB and engine state
- Also clears positions table and processed_recommendation_ids on reset
- Broker reset is best-effort — DB/engine reset proceeds even if Alpaca fails

services/trading/app.py

@@ -407,6 +407,9 @@ async def reset_paper_trading(body: CapitalRequest) -> dict[str, Any]:
     """Full paper trading reset: clear all positions, orders, decisions,
     stop levels, and snapshots, then reset capital to the specified amount.
 
+    Also liquidates all positions and cancels all open orders on the
+    broker (Alpaca) so the paper account starts clean.
+
     This is a destructive operation — all trading history is wiped.
     """
     if engine is None:
@@ -420,7 +423,32 @@ async def reset_paper_trading(body: CapitalRequest) -> dict[str, Any]:
     reserve = capital * reserve_pct
     active = capital - reserve
 
-    # Clear trading state in the database
+    # --- Reset broker (Alpaca) state ---
+    broker_result: dict[str, Any] = {"orders_cancelled": 0, "positions_closed": 0}
+    try:
+        from services.adapters.broker_adapter import AlpacaBrokerAdapter
+        from services.shared.config import load_config as _load_config
+
+        broker_cfg = _load_config().broker
+        if broker_cfg.api_key:
+            adapter = AlpacaBrokerAdapter(
+                api_key=broker_cfg.api_key,
+                api_secret=broker_cfg.api_secret or "",
+                base_url=broker_cfg.base_url,
+            )
+            broker_result["orders_cancelled"] = await adapter.cancel_all_orders()
+            broker_result["positions_closed"] = await adapter.close_all_positions()
+            logger.info(
+                "Broker reset: cancelled %d orders, closed %d positions",
+                broker_result["orders_cancelled"],
+                broker_result["positions_closed"],
+            )
+        else:
+            logger.info("No broker API key configured — skipping broker reset")
+    except Exception:
+        logger.exception("Broker reset failed — continuing with DB/engine reset")
+
+    # --- Clear trading state in the database ---
     if engine.pool:
         try:
             async with engine.pool.acquire() as conn:
@@ -438,6 +466,8 @@ async def reset_paper_trading(body: CapitalRequest) -> dict[str, Any]:
                     # Clear orders and their events
                     await conn.execute("DELETE FROM order_events")
                     await conn.execute("DELETE FROM orders")
+                    # Clear synced positions from broker
+                    await conn.execute("DELETE FROM positions")
                     # Re-seed reserve pool ledger
                     await conn.execute(
                         "INSERT INTO reserve_pool_ledger (amount, balance_after, trigger_type, notes) "
@@ -458,12 +488,14 @@ async def reset_paper_trading(body: CapitalRequest) -> dict[str, Any]:
         reserve_pool=reserve,
     )
     engine.circuit_breaker_state = CircuitBreakerState()
+    engine.processed_recommendation_ids.clear()
 
     return {
         "reset": True,
         "initial_capital": capital,
         "active_pool": active,
         "reserve_pool": reserve,
+        "broker": broker_result,
     }