Add agent-as-editor panels, intent dispatch, and shared components
for workflow page types on the kurt-simplification branch base.

Backend:
- parser.py: Add PageConfig, ColumnConfig, SceneConfig, TransitionConfig
  models with pages parsing in TOML/MD workflows and validation
- registry.py: Add find_definition_by_workflow_id(), get_page_config(),
  get_definition_for_workflow() helpers using DoltDB
- routes/pages.py: New route module with page data, edit dispatch,
  asset manifest endpoints
- routes/files.py: Add /api/file/raw endpoint for media file serving
- intent_dispatch.py: Intent-to-prompt conversion for agent editing

Frontend:
- DataTablePanel: Editable spreadsheet with seed data support
- ImageViewerPanel: Image viewer with zoom and intent toolbar
- MotionCanvasPanel: MC rendered output viewer with transport controls
- VideoEditorPanel: Video player with trim/cut and intent dispatch
- VideoSequencePanel: Multi-scene composition timeline
- IntentToolbar: Shared intent capture (add text, shape, move, resize)
- ShapePicker: SVG shape library browser
- TextOverlayPopover: Text/font/color input for text intents
- useFileWatch: Hook for polling file mtime changes
- WorkflowRow: Page buttons with icons for each page type
- App.jsx: PAGE_TYPE_TO_COMPONENT mapping and openWorkflowPage callback
- styles.css: Complete CSS for all panels using design token system

Docs:
- CLAUDE.md: Workflow Pages section with architecture, page types,
  API endpoints, and asset configuration

https://claude.ai/code/session_016p3y4FpBYpbKsoABaeG4ft