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_prompt_fields.py

@@ -0,0 +1,36 @@
+"""add prompt fields to assets and storyboards
+
+Revision ID: add_prompt_fields
+Revises: add_task_mgmt_fields
+Create Date: 2026-01-16
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'add_prompt_fields'
+down_revision = 'add_task_mgmt_fields'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Add image_prompt to assets table
+    op.add_column('assets', sa.Column('image_prompt', sa.String(), nullable=True))
+    
+    # Add prompt fields to storyboards table
+    op.add_column('storyboards', sa.Column('original_text', sa.String(), nullable=True))
+    op.add_column('storyboards', sa.Column('merge_image_prompt', sa.String(), nullable=True))
+    op.add_column('storyboards', sa.Column('video_prompt', sa.String(), nullable=True))
+
+
+def downgrade() -> None:
+    # Remove fields from storyboards
+    op.drop_column('storyboards', 'video_prompt')
+    op.drop_column('storyboards', 'merge_image_prompt')
+    op.drop_column('storyboards', 'original_text')
+    
+    # Remove field from assets
+    op.drop_column('assets', 'image_prompt')