Implement the following plan:

# Video Production Studio — Implementation Plan

## Context
The current /generate/video page is a static read-only script reference. We're transforming it into a **live production studio** where the user:
1. Views the script and generates Anky images per scene
2. Records themselves reading the script via in-browser camera (MediaRecorder API)
3. Reviews the recording and uploads it to the server

The script drives everything. One continuous take with auto-scrolling teleprompter. Image generation auto-triggers from pre-written scene prompts.

## Files to Modify

| File | Change |
|------|--------|
| `templates/video.html` | **Complete rewrite** → 3-phase studio (prep/record/review) with MediaRecorder, teleprompter, upload |
| `static/style.css` | Replace `.video-*` styles with `.studio-*` classes for all 3 phases, teleprompter, camera PIP, timeline |
| `src/routes/api.rs` | Add `upload_studio_video()` — multipart video upload handler |
| `src/routes/mod.rs` | Add route: `/api/v1/studio/upload` |
| `src/db/migrations.rs` | Add `video_recordings` table |
| `src/db/queries.rs` | Add `insert_video_recording()` + `update_video_status()` |

## Implementation Steps

### 1. Database: `video_recordings` table
### 2. Upload endpoint (`src/routes/api.rs`)
### 3. Template rewrite (`templates/video.html`) — Three phases managed by JS state machine
### 4. CSS changes — New `.studio-*` classes
### 5. Patterns reused from existing code (timer, countdown, immersive mode, image generation)
### 6. Script data structure (hardcoded in template JS)

## Verification
1. `cargo build --release` — compiles with new upload handler + DB migration
2. Visit `/generate/video` — see PREP phase with script + image grid
3. Click generate on an image prompt — see Anky image appear
4. Click START RECORDING — countdown, camera preview, teleprompter scrolls
5. Click STOP — review phase with playback
6. Click UPLOAD — video saved to `data/videos/`, DB record created
7. Test on phone — front-facing camera, readable teleprompter