Initial commit: Pixel AI comic/video creation platform

- FastAPI backend with SQLModel, Alembic migrations, AgentScope agents
- Next.js 15 frontend with React 19, Tailwind, Zustand, React Flow
- Multi-provider AI system (DashScope, Kling, MiniMax, Volcengine, OpenAI, etc.)
- All HTTP clients migrated from sync requests to async httpx
- Admin-managed API keys via environment variables
- SSRF vulnerability fixed in ensure_url()

backend/alembic/versions/add_task_management_fields.py

@@ -0,0 +1,50 @@
+"""add task management fields
+
+Revision ID: add_task_mgmt_fields
+Revises: add_indexes_opt
+Create Date: 2026-01-14
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'add_task_mgmt_fields'
+down_revision = 'add_indexes_opt'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Add retry configuration fields
+    op.add_column('tasks', sa.Column('retry_count', sa.Integer(), nullable=False, server_default='0'))
+    op.add_column('tasks', sa.Column('max_retries', sa.Integer(), nullable=False, server_default='3'))
+    
+    # Add timestamp fields for task lifecycle
+    op.add_column('tasks', sa.Column('started_at', sa.Float(), nullable=True))
+    op.add_column('tasks', sa.Column('completed_at', sa.Float(), nullable=True))
+    
+    # Add user context fields
+    op.add_column('tasks', sa.Column('user_id', sa.String(), nullable=True))
+    op.add_column('tasks', sa.Column('project_id', sa.String(), nullable=True))
+    
+    # Add indexes for new fields
+    op.create_index('idx_tasks_user_id', 'tasks', ['user_id'])
+    op.create_index('idx_tasks_project_id', 'tasks', ['project_id'])
+    
+    # Note: deleted_at column already exists from previous migration
+
+
+def downgrade():
+    # Remove indexes
+    op.drop_index('idx_tasks_project_id', table_name='tasks')
+    op.drop_index('idx_tasks_user_id', table_name='tasks')
+    
+    # Remove columns
+    op.drop_column('tasks', 'project_id')
+    op.drop_column('tasks', 'user_id')
+    op.drop_column('tasks', 'completed_at')
+    op.drop_column('tasks', 'started_at')
+    op.drop_column('tasks', 'max_retries')
+    op.drop_column('tasks', 'retry_count')