feat(web): gender-differentiated 4:5 covers + per-card styleGuide prebake

- Regenerate 60 covers (30 male + 30 female) via FLUX with story-specific
  prompts, replacing the prior gender-shared set
- Crop covers to 4:5 (960×1200) via sharp attention cover; matches new
  homepage card aspectRatio
- Persist all 60 prompts to public/home/prompts.json so the prebake step
  can reuse the cover's exact visual anchor (per-card styleGuide) and the
  first-act scene visually carries over from the poster the player clicked
- Restore /play?card= prebaked instant-play path on homepage card click
- Add OpenAI-compatible image route in ai-client for non-Runware endpoints
- Hide Next.js dev indicators globally; tweak F-key fullscreen label

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

app/play/page.tsx

@@ -962,7 +962,7 @@ function PlayInner() {
               title="全屏 (F)"
             >
               <i className="fa-solid fa-expand text-[10px]" />
-              F · 全 · 屏
+              F · 键 · 全 · 屏
             </button>
           }
           aboveCanvasLeft={