feat: add Remotion project scaffolding and subtitle tools

Remotion project:
- package.json with Remotion 4.0.522, React 19, Tailwind v4
- tsconfig.json (strict, ES2018, Bundler module resolution)
- remotion.config.ts (rspack, jpeg image format)
- ESLint flat config, Prettier config
- Root component and MyComposition placeholder (1280x720, 30fps, 60 frames)

Subtitle tools:
- src/lrc2srt.ts — LRC to SRT converter (minimal, no dependencies)
- ffmpeg.sh — helper for baking ASS subtitles or static-image+audio bypass

tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2018",
+    "module": "Preserve",
+    "moduleResolution": "Bundler",
+    "jsx": "react-jsx",
+    "strict": true,
+    "noEmit": true,
+    "lib": ["es2015"],
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "noUnusedLocals": true
+  },
+  "exclude": ["remotion.config.ts"]
+}