feat: Vercel Hobby deploy readiness — image URLs, jsonrepair, DeepSeek

- Move vercel.json to apps/web/ with correct route paths; cap scene route
  maxDuration 120→60s for Hobby. Root vercel.json removed. Vercel project's
  Root Directory must be set to apps/web (Deploy button URL passes this).
- Switch image transport from base64-in-JSON to Runware-hosted URLs:
  generateImage now uses outputType=URL and returns {imageUrl, imageUuid};
  StartResponse/SceneResponse carry imageUrl; VisionRequest carries
  prevImageUrl (server re-fetches the bytes for click annotation). This
  eliminates the 4.5MB serverless body-size risk.
- Painter and director prefer URL over UUID for referenceImages — the UUID
  returned by Runware imageInference isn't always recognized in the refs
  pipeline (surfaces as `failedToTransferImage`).
- Client preloads scene images via `new Image().decode()` before committing
  to React state, so URL transitions render instantly; prefetched scenes
  also warm the HTTP cache.
- jsonParser uses the jsonrepair package (replaces hand-rolled repair) and
  adds a targeted preRepair regex for the missing-key-close-quote pattern
  that jsonrepair couldn't disambiguate. Full raw model output dumped on
  failure for diagnostic visibility.
- Default text provider switched to DeepSeek v4-flash via direct API
  (significantly more stable JSON than MiMo v2.5-pro). VISION/TTS stay on
  MiMo (DeepSeek has no multimodal / TTS offerings).
- next.config: drop dead experimental.serverActions.bodySizeLimit (no
  server actions used).
- README: real Deploy button URL (zonghaoyuan/yume + root-directory=apps/web
  + TTS/MOCK_IMAGE in env list); refreshed env vars table with optional
  TTS section.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pnpm-lock.yaml

@@ -75,6 +75,9 @@ importers:
       '@yume/types':
         specifier: workspace:*
         version: link:../types
+      jsonrepair:
+        specifier: ^3.14.0
+        version: 3.14.0
       sharp:
         specifier: ^0.33.5
         version: 0.33.5
@@ -594,6 +597,10 @@ packages:
     resolution: {integrity: sha512-/imKNG4EbWNrVjoNC/1H5/9GFy+tqjGBHCaSsN+P2RnPqjsLmv6UD3Ej+Kj8nBWaRAwyk7kK5ZUc+OEatnTR3A==}
     hasBin: true
 
+  jsonrepair@3.14.0:
+    resolution: {integrity: sha512-tWPGKMZf/8UPim+fcW2EfcQ/d/7aKUrP6IECz9G3Tu6Q5dX0orSleqJ9z6sSw7qrQkjF8/Edo4DvsWBZ8H+HNg==}
+    hasBin: true
+
   lilconfig@3.1.3:
     resolution: {integrity: sha512-/vlFKAoH5Cgt3Ie+JLhRbwOsCQePABiU3tJ1egGvyQ+33R/vcwM2Zl2QR/LzjsBeItPt3oSVXapn+m4nQDvpzw==}
     engines: {node: '>=14'}
@@ -1240,6 +1247,8 @@ snapshots:
 
   jiti@1.21.7: {}
 
+  jsonrepair@3.14.0: {}
+
   lilconfig@3.1.3: {}
 
   lines-and-columns@1.2.4: {}