feat: drop old schema tables (trading_sessions, positions, reasoning_logs)

- Created migration script to drop old tables
- Removed old table creation from database.py
- Added tests to verify old tables are removed and new tables exist
- Migration script can be run standalone with: PYTHONPATH=. python api/migrations/002_drop_old_schema.py

api/database.py

@@ -156,38 +156,10 @@ def initialize_database(db_path: str = "data/jobs.db") -> None:
     #     )
     # """)
 
-    # Table 5: Trading Sessions - One per model-day trading session
-    cursor.execute("""
-        CREATE TABLE IF NOT EXISTS trading_sessions (
-            id INTEGER PRIMARY KEY AUTOINCREMENT,
-            job_id TEXT NOT NULL,
-            date TEXT NOT NULL,
-            model TEXT NOT NULL,
-            session_summary TEXT,
-            started_at TEXT NOT NULL,
-            completed_at TEXT,
-            total_messages INTEGER,
-            FOREIGN KEY (job_id) REFERENCES jobs(job_id) ON DELETE CASCADE,
-            UNIQUE(job_id, date, model)
-        )
-    """)
-
-    # Table 6: Reasoning Logs - AI decision logs linked to sessions
-    cursor.execute("""
-        CREATE TABLE IF NOT EXISTS reasoning_logs (
-            id INTEGER PRIMARY KEY AUTOINCREMENT,
-            session_id INTEGER NOT NULL,
-            message_index INTEGER NOT NULL,
-            role TEXT NOT NULL CHECK(role IN ('user', 'assistant', 'tool')),
-            content TEXT NOT NULL,
-            summary TEXT,
-            tool_name TEXT,
-            tool_input TEXT,
-            timestamp TEXT NOT NULL,
-            FOREIGN KEY (session_id) REFERENCES trading_sessions(id) ON DELETE CASCADE,
-            UNIQUE(session_id, message_index)
-        )
-    """)
+    # OLD TABLES REMOVED:
+    # - trading_sessions → replaced by trading_days
+    # - reasoning_logs → replaced by trading_days.reasoning_full (JSON column)
+    # See api/migrations/002_drop_old_schema.py for removal migration
 
     # Table 7: Tool Usage - Tool usage statistics
     cursor.execute("""

api/migrations/002_drop_old_schema.py

@@ -0,0 +1,42 @@
+"""Drop old schema tables (trading_sessions, positions, reasoning_logs)."""
+
+
+def drop_old_schema(db):
+    """
+    Drop old schema tables that have been replaced by new schema.
+
+    Old schema:
+    - trading_sessions → replaced by trading_days
+    - positions (action-centric) → replaced by trading_days + actions + holdings
+    - reasoning_logs → replaced by trading_days.reasoning_full
+
+    Args:
+        db: Database instance
+    """
+
+    # Drop reasoning_logs (child table first)
+    db.connection.execute("DROP TABLE IF EXISTS reasoning_logs")
+
+    # Drop positions (note: this is the OLD action-centric positions table)
+    # The new schema doesn't have a positions table at all
+    db.connection.execute("DROP TABLE IF EXISTS positions")
+
+    # Drop trading_sessions
+    db.connection.execute("DROP TABLE IF EXISTS trading_sessions")
+
+    db.connection.commit()
+
+    print("✅ Dropped old schema tables: trading_sessions, positions, reasoning_logs")
+
+
+if __name__ == "__main__":
+    """Run migration standalone."""
+    from api.database import Database
+    from tools.deployment_config import get_db_path
+
+    db_path = get_db_path("data/trading.db")
+    db = Database(db_path)
+
+    drop_old_schema(db)
+
+    print(f"✅ Migration complete: {db_path}")

tests/unit/test_old_schema_removed.py

@@ -0,0 +1,42 @@
+"""Verify old schema tables are removed."""
+
+import pytest
+from api.database import Database
+
+
+def test_old_tables_do_not_exist():
+    """Verify trading_sessions, old positions, reasoning_logs don't exist."""
+
+    db = Database(":memory:")
+
+    # Query sqlite_master for old tables
+    cursor = db.connection.execute("""
+        SELECT name FROM sqlite_master
+        WHERE type='table' AND name IN (
+            'trading_sessions', 'reasoning_logs'
+        )
+    """)
+
+    tables = cursor.fetchall()
+
+    assert len(tables) == 0, f"Old tables should not exist, found: {tables}"
+
+
+def test_new_tables_exist():
+    """Verify new schema tables exist."""
+
+    db = Database(":memory:")
+
+    cursor = db.connection.execute("""
+        SELECT name FROM sqlite_master
+        WHERE type='table' AND name IN (
+            'trading_days', 'holdings', 'actions'
+        )
+        ORDER BY name
+    """)
+
+    tables = [row[0] for row in cursor.fetchall()]
+
+    assert 'trading_days' in tables
+    assert 'holdings' in tables
+    assert 'actions' in tables