fix: enable cross-job portfolio continuity in get_previous_trading_day

Remove job_id filter from get_previous_trading_day() SQL query to enable
portfolio continuity across jobs. Previously, new jobs would reset to
initial $10,000 cash instead of continuing from previous job's ending
position.

Root cause: get_previous_trading_day() filtered by job_id, while
get_current_position_from_db() correctly queries across all jobs.
This inconsistency caused starting_cash to default to initial_cash
when no previous day was found within the same job.

Changes:
- api/database.py: Remove job_id filter from SQL WHERE clause
- tests/unit/test_database_helpers.py: Add test for cross-job continuity

Fixes position tracking bug where subsequent jobs on consecutive dates
would not recognize previous day's holdings from different job.

CHANGELOG.md

@@ -7,6 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.4.2] - 2025-11-07
+
+### Fixed
+- **Critical:** Fixed negative cash position bug where trades calculated from initial capital instead of accumulating
+  - Root cause: MCP tools return `CallToolResult` objects with position data in `structuredContent` field, but `ContextInjector` was checking `isinstance(result, dict)` which always failed
+  - Impact: Each trade checked cash against initial $10,000 instead of cumulative position, allowing over-spending and resulting in negative cash balances (e.g., -$8,768.68 after 11 trades totaling $18,768.68)
+  - Solution: Updated `ContextInjector` to extract position dict from `CallToolResult.structuredContent` before validation
+  - Fix ensures proper intra-day position tracking with cumulative cash checks preventing over-trading
+  - Updated unit tests to mock `CallToolResult` objects matching production MCP behavior
+  - Locations: `agent/context_injector.py:95-109`, `tests/unit/test_context_injector.py:26-53`
+- Enabled MCP service logging by redirecting stdout/stderr from `/dev/null` to main process for better debugging
+  - Previously, all MCP tool debug output was silently discarded
+  - Now visible in docker logs for diagnosing parameter injection and trade execution issues
+  - Location: `agent_tools/start_mcp_services.py:81-88`
+
 ### Fixed
 - **Critical:** Fixed stale jobs blocking new jobs after Docker container restart
   - Root cause: Jobs with status 'pending', 'downloading_data', or 'running' remained in database after container shutdown, preventing new job creation

agent/context_injector.py

@@ -88,28 +88,17 @@ class ContextInjector:
 
         # Update position state after successful trade
         if request.name in ["buy", "sell"]:
-            # Debug: Log result type and structure
-            print(f"[DEBUG ContextInjector] Trade result type: {type(result)}")
-            print(f"[DEBUG ContextInjector] Trade result: {result}")
-
             # Extract position dict from MCP result
             # MCP tools return CallToolResult objects with structuredContent field
             position_dict = None
             if hasattr(result, 'structuredContent') and result.structuredContent:
                 position_dict = result.structuredContent
-                print(f"[DEBUG ContextInjector] Extracted from structuredContent: {position_dict}")
             elif isinstance(result, dict):
                 position_dict = result
-                print(f"[DEBUG ContextInjector] Using result as dict: {position_dict}")
 
             # Check if position dict is valid (not an error) and update state
             if position_dict and "error" not in position_dict and "CASH" in position_dict:
                 # Update our tracked position with the new state
                 self._current_position = position_dict.copy()
-                print(f"[DEBUG ContextInjector] Updated _current_position: {self._current_position}")
-            else:
-                print(f"[DEBUG ContextInjector] Did NOT update _current_position - check failed")
-                print(f"[DEBUG ContextInjector] position_dict: {position_dict}")
-                print(f"[DEBUG ContextInjector] _current_position remains: {self._current_position}")
 
         return result

agent_tools/tool_trade.py

@@ -132,14 +132,11 @@ def _buy_impl(symbol: str, amount: int, signature: str = None, today_date: str =
         # Step 1: Get current position
         # Use injected position if available (for intra-day tracking),
         # otherwise query database for starting position
-        print(f"[DEBUG buy] _current_position received: {_current_position}")
         if _current_position is not None:
             current_position = _current_position
             next_action_id = 0  # Not used in new schema
-            print(f"[DEBUG buy] Using injected position: {current_position}")
         else:
             current_position, next_action_id = get_current_position_from_db(job_id, signature, today_date)
-            print(f"[DEBUG buy] Queried position from DB: {current_position}")
 
         # Step 2: Get stock price
         try:
@@ -192,8 +189,6 @@ def _buy_impl(symbol: str, amount: int, signature: str = None, today_date: str =
 
         conn.commit()
         print(f"[buy] {signature} bought {amount} shares of {symbol} at ${this_symbol_price}")
-        print(f"[DEBUG buy] Returning new_position: {new_position}")
-        print(f"[DEBUG buy] new_position keys: {list(new_position.keys())}")
         return new_position
 
     except Exception as e:

api/database.py

@@ -611,6 +611,10 @@ class Database:
 
         Handles weekends/holidays by finding actual previous trading day.
 
+        NOTE: Queries across ALL jobs for the given model to enable portfolio
+        continuity even when new jobs are created with overlapping date ranges.
+        The job_id parameter is kept for API compatibility but not used in the query.
+
         Returns:
             dict with keys: id, date, ending_cash, ending_portfolio_value
             or None if no previous day exists
@@ -619,11 +623,11 @@ class Database:
             """
             SELECT id, date, ending_cash, ending_portfolio_value
             FROM trading_days
-            WHERE job_id = ? AND model = ? AND date < ?
+            WHERE model = ? AND date < ?
             ORDER BY date DESC
             LIMIT 1
             """,
-            (job_id, model, current_date)
+            (model, current_date)
         )
 
         row = cursor.fetchone()

tests/unit/test_database_helpers.py

@@ -130,6 +130,44 @@ class TestDatabaseHelpers:
         assert previous is not None
         assert previous["date"] == "2025-01-17"
 
+    def test_get_previous_trading_day_across_jobs(self, db):
+        """Test retrieving previous trading day from different job (cross-job continuity)."""
+        # Setup: Create two jobs
+        db.connection.execute(
+            "INSERT INTO jobs (job_id, status, config_path, date_range, models, created_at) VALUES (?, ?, ?, ?, ?, ?)",
+            ("job-1", "completed", "config.json", "2025-10-07,2025-10-07", "deepseek-chat-v3.1", "2025-11-07T00:00:00Z")
+        )
+        db.connection.execute(
+            "INSERT INTO jobs (job_id, status, config_path, date_range, models, created_at) VALUES (?, ?, ?, ?, ?, ?)",
+            ("job-2", "running", "config.json", "2025-10-08,2025-10-08", "deepseek-chat-v3.1", "2025-11-07T01:00:00Z")
+        )
+
+        # Day 1 in job-1
+        db.create_trading_day(
+            job_id="job-1",
+            model="deepseek-chat-v3.1",
+            date="2025-10-07",
+            starting_cash=10000.0,
+            starting_portfolio_value=10000.0,
+            daily_profit=214.58,
+            daily_return_pct=2.15,
+            ending_cash=123.59,
+            ending_portfolio_value=10214.58
+        )
+
+        # Test: Get previous day from job-2 on next date
+        # Should find job-1's record (cross-job continuity)
+        previous = db.get_previous_trading_day(
+            job_id="job-2",
+            model="deepseek-chat-v3.1",
+            current_date="2025-10-08"
+        )
+
+        assert previous is not None
+        assert previous["date"] == "2025-10-07"
+        assert previous["ending_cash"] == 123.59
+        assert previous["ending_portfolio_value"] == 10214.58
+
     def test_get_ending_holdings(self, db):
         """Test retrieving ending holdings for a trading day."""
         db.connection.execute(