test: improve test coverage from 61% to 84.81%

Major improvements:
- Fixed all 42 broken tests (database connection leaks)
- Added db_connection() context manager for proper cleanup
- Created comprehensive test suites for undertested modules

New test coverage:
- tools/general_tools.py: 26 tests (97% coverage)
- tools/price_tools.py: 11 tests (validates NASDAQ symbols, date handling)
- api/price_data_manager.py: 12 tests (85% coverage)
- api/routes/results_v2.py: 3 tests (98% coverage)
- agent/reasoning_summarizer.py: 2 tests (87% coverage)
- api/routes/period_metrics.py: 2 edge case tests (100% coverage)
- agent/mock_provider: 1 test (100% coverage)

Database fixes:
- Added db_connection() context manager to prevent leaks
- Updated 16+ test files to use context managers
- Fixed drop_all_tables() to match new schema
- Added CHECK constraint for action_type
- Added ON DELETE CASCADE to trading_days foreign key

Test improvements:
- Updated SQL INSERT statements with all required fields
- Fixed date parameter handling in API integration tests
- Added edge case tests for validation functions
- Fixed import errors across test suite

Results:
- Total coverage: 84.81% (was 61%)
- Tests passing: 406 (was 364 with 42 failures)
- Total lines covered: 6364 of 7504

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

tests/unit/test_model_day_executor_reasoning.py

@@ -13,14 +13,13 @@ def test_db(tmp_path):
     initialize_database(db_path)
 
     # Create a job record to satisfy foreign key constraint
-    conn = get_db_connection(db_path)
-    cursor = conn.cursor()
-    cursor.execute("""
-        INSERT INTO jobs (job_id, config_path, status, date_range, models, created_at)
-        VALUES ('test-job', 'configs/default_config.json', 'running', '["2025-01-01"]', '["test-model"]', '2025-01-01T00:00:00Z')
-    """)
-    conn.commit()
-    conn.close()
+    with db_connection(db_path) as conn:
+        cursor = conn.cursor()
+        cursor.execute("""
+            INSERT INTO jobs (job_id, config_path, status, date_range, models, created_at)
+            VALUES ('test-job', 'configs/default_config.json', 'running', '["2025-01-01"]', '["test-model"]', '2025-01-01T00:00:00Z')
+        """)
+        conn.commit()
 
     return db_path
 
@@ -36,23 +35,22 @@ def test_create_trading_session(test_db):
         db_path=test_db
     )
 
-    conn = get_db_connection(test_db)
-    cursor = conn.cursor()
+    with db_connection(test_db) as conn:
+        cursor = conn.cursor()
 
-    session_id = executor._create_trading_session(cursor)
-    conn.commit()
+        session_id = executor._create_trading_session(cursor)
+        conn.commit()
 
-    # Verify session created
-    cursor.execute("SELECT * FROM trading_sessions WHERE id = ?", (session_id,))
-    session = cursor.fetchone()
+        # Verify session created
+        cursor.execute("SELECT * FROM trading_sessions WHERE id = ?", (session_id,))
+        session = cursor.fetchone()
 
-    assert session is not None
-    assert session['job_id'] == "test-job"
-    assert session['date'] == "2025-01-01"
-    assert session['model'] == "test-model"
-    assert session['started_at'] is not None
+        assert session is not None
+        assert session['job_id'] == "test-job"
+        assert session['date'] == "2025-01-01"
+        assert session['model'] == "test-model"
+        assert session['started_at'] is not None
 
-    conn.close()
 
 
 @pytest.mark.skip(reason="Methods removed in schema migration Task 2. Will be deleted in Task 6.")
@@ -85,27 +83,26 @@ async def test_store_reasoning_logs(test_db):
         {"role": "assistant", "content": "Bought AAPL 10 shares based on strong earnings", "timestamp": "2025-01-01T10:05:00Z"}
     ]
 
-    conn = get_db_connection(test_db)
-    cursor = conn.cursor()
-    session_id = executor._create_trading_session(cursor)
+    with db_connection(test_db) as conn:
+        cursor = conn.cursor()
+        session_id = executor._create_trading_session(cursor)
 
-    await executor._store_reasoning_logs(cursor, session_id, conversation, agent)
-    conn.commit()
+        await executor._store_reasoning_logs(cursor, session_id, conversation, agent)
+        conn.commit()
 
-    # Verify logs stored
-    cursor.execute("SELECT * FROM reasoning_logs WHERE session_id = ? ORDER BY message_index", (session_id,))
-    logs = cursor.fetchall()
+        # Verify logs stored
+        cursor.execute("SELECT * FROM reasoning_logs WHERE session_id = ? ORDER BY message_index", (session_id,))
+        logs = cursor.fetchall()
 
-    assert len(logs) == 2
-    assert logs[0]['role'] == 'user'
-    assert logs[0]['content'] == 'Analyze market'
-    assert logs[0]['summary'] is None  # No summary for user messages
+        assert len(logs) == 2
+        assert logs[0]['role'] == 'user'
+        assert logs[0]['content'] == 'Analyze market'
+        assert logs[0]['summary'] is None  # No summary for user messages
 
-    assert logs[1]['role'] == 'assistant'
-    assert logs[1]['content'] == 'Bought AAPL 10 shares based on strong earnings'
-    assert logs[1]['summary'] is not None  # Summary generated for assistant
+        assert logs[1]['role'] == 'assistant'
+        assert logs[1]['content'] == 'Bought AAPL 10 shares based on strong earnings'
+        assert logs[1]['summary'] is not None  # Summary generated for assistant
 
-    conn.close()
 
 
 @pytest.mark.skip(reason="Methods removed in schema migration Task 2. Will be deleted in Task 6.")
@@ -139,23 +136,22 @@ async def test_update_session_summary(test_db):
         {"role": "assistant", "content": "Sold MSFT 5 shares", "timestamp": "2025-01-01T10:10:00Z"}
     ]
 
-    conn = get_db_connection(test_db)
-    cursor = conn.cursor()
-    session_id = executor._create_trading_session(cursor)
+    with db_connection(test_db) as conn:
+        cursor = conn.cursor()
+        session_id = executor._create_trading_session(cursor)
 
-    await executor._update_session_summary(cursor, session_id, conversation, agent)
-    conn.commit()
+        await executor._update_session_summary(cursor, session_id, conversation, agent)
+        conn.commit()
 
-    # Verify session updated
-    cursor.execute("SELECT * FROM trading_sessions WHERE id = ?", (session_id,))
-    session = cursor.fetchone()
+        # Verify session updated
+        cursor.execute("SELECT * FROM trading_sessions WHERE id = ?", (session_id,))
+        session = cursor.fetchone()
 
-    assert session['session_summary'] is not None
-    assert len(session['session_summary']) > 0
-    assert session['completed_at'] is not None
-    assert session['total_messages'] == 3
+        assert session['session_summary'] is not None
+        assert len(session['session_summary']) > 0
+        assert session['completed_at'] is not None
+        assert session['total_messages'] == 3
 
-    conn.close()
 
 
 @pytest.mark.skip(reason="Methods removed in schema migration Task 2. Will be deleted in Task 6.")
@@ -195,24 +191,23 @@ async def test_store_reasoning_logs_with_tool_messages(test_db):
         {"role": "assistant", "content": "AAPL is $150", "timestamp": "2025-01-01T10:02:00Z"}
     ]
 
-    conn = get_db_connection(test_db)
-    cursor = conn.cursor()
-    session_id = executor._create_trading_session(cursor)
+    with db_connection(test_db) as conn:
+        cursor = conn.cursor()
+        session_id = executor._create_trading_session(cursor)
 
-    await executor._store_reasoning_logs(cursor, session_id, conversation, agent)
-    conn.commit()
+        await executor._store_reasoning_logs(cursor, session_id, conversation, agent)
+        conn.commit()
 
-    # Verify tool message stored correctly
-    cursor.execute("SELECT * FROM reasoning_logs WHERE session_id = ? AND role = 'tool'", (session_id,))
-    tool_log = cursor.fetchone()
+        # Verify tool message stored correctly
+        cursor.execute("SELECT * FROM reasoning_logs WHERE session_id = ? AND role = 'tool'", (session_id,))
+        tool_log = cursor.fetchone()
 
-    assert tool_log is not None
-    assert tool_log['tool_name'] == 'get_price'
-    assert tool_log['tool_input'] == '{"symbol": "AAPL"}'
-    assert tool_log['content'] == 'AAPL: $150.00'
-    assert tool_log['summary'] is None  # No summary for tool messages
+        assert tool_log is not None
+        assert tool_log['tool_name'] == 'get_price'
+        assert tool_log['tool_input'] == '{"symbol": "AAPL"}'
+        assert tool_log['content'] == 'AAPL: $150.00'
+        assert tool_log['summary'] is None  # No summary for tool messages
 
-    conn.close()
 
 
 @pytest.mark.skip(reason="Method _write_results_to_db() removed - positions written by trade tools")