Add migration for assignment_type column

- Creates migration 004_add_assignment_type.py
- Adds assignment_type VARCHAR(20) to chores table
- Default value: 'any_one' for backward compatibility
- Values: 'any_one' (only one needs to complete) or 'all_assigned' (all must complete)
- Safe to run on existing database

backend/migrations/004_add_assignment_type.py

@@ -0,0 +1,40 @@
+"""Add assignment_type to chores table."""
+import sqlite3
+import sys
+from pathlib import Path
+
+# Add parent directory to path to import from app
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+def upgrade():
+    """Add assignment_type column to chores table."""
+    db_path = Path(__file__).parent.parent / "data" / "family_hub.db"
+    
+    print(f"Connecting to database: {db_path}")
+    conn = sqlite3.connect(db_path)
+    cursor = conn.cursor()
+    
+    try:
+        # Add assignment_type column (default 'any_one' for backward compatibility)
+        print("Adding assignment_type column to chores table...")
+        cursor.execute("""
+            ALTER TABLE chores 
+            ADD COLUMN assignment_type VARCHAR(20) DEFAULT 'any_one'
+        """)
+        
+        conn.commit()
+        print("✅ Successfully added assignment_type column")
+        print("   Values: 'any_one' (only one person needs to complete)")
+        print("          'all_assigned' (all assigned people must complete)")
+        
+    except sqlite3.OperationalError as e:
+        if "duplicate column name" in str(e).lower():
+            print("⚠️  Column assignment_type already exists, skipping...")
+        else:
+            raise
+    finally:
+        conn.close()
+
+if __name__ == "__main__":
+    upgrade()
+    print("\n✅ Migration completed!")