Set up Alembic database migrations with initial Todo table migration

- Initialize Alembic in migrations/ directory (not alembic/)
- Configure alembic.ini with correct SQLite absolute path: sqlite:////app/storage/db/db.sqlite
- Configure migrations/env.py to import Base correctly from app.db.base using absolute imports
- Create initial migration 0001_initial_todo_table.py for Todo model
- Migration creates todos table with id, title, description, completed, created_at, updated_at fields
- Includes proper indexes for id (primary key) and title fields
- Uses absolute imports to avoid ModuleNotFoundError issues
- Follows exact specifications for SQLite URL and import paths

migrations/__init__.py

@@ -0,0 +1 @@
+# Alembic migrations package

migrations/env.py

@@ -1,15 +1,21 @@
+import sys
+from pathlib import Path
 from logging.config import fileConfig
+
 from sqlalchemy import engine_from_config
 from sqlalchemy import pool
+
 from alembic import context
-import sys
-import os
 
 # Add the project root to the Python path
-sys.path.append(os.path.dirname(os.path.dirname(__file__)))
+sys.path.insert(0, str(Path(__file__).parent.parent))
 
+# Import the Base from the correct location
 from app.db.base import Base
 
+# Import all models so they are available to Alembic
+from app.models.todo import Todo
+
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
@@ -61,7 +67,7 @@ def run_migrations_online() -> None:
 
     """
     connectable = engine_from_config(
-        config.get_section(config.config_ini_section, {}),
+        config.get_section(config.config_ini_section),
         prefix="sqlalchemy.",
         poolclass=pool.NullPool,
     )

migrations/versions/0001_initial_todo_table.py

@@ -0,0 +1,39 @@
+"""Initial todo table
+
+Revision ID: 0001
+Revises: 
+Create Date: 2025-06-20 23:16:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '0001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create todos table
+    op.create_table(
+        'todos',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(length=255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('completed', sa.Boolean(), nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('updated_at', sa.DateTime(), nullable=False),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_todos_id'), 'todos', ['id'], unique=False)
+    op.create_index(op.f('ix_todos_title'), 'todos', ['title'], unique=False)
+
+
+def downgrade() -> None:
+    # Drop todos table
+    op.drop_index(op.f('ix_todos_title'), table_name='todos')
+    op.drop_index(op.f('ix_todos_id'), table_name='todos')
+    op.drop_table('todos')

migrations/versions/__init__.py

@@ -0,0 +1 @@
+# Alembic migration versions package