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

remotion.config.ts

@@ -0,0 +1,14 @@
+/**
+ * Note: When using the Node.JS APIs, the config file
+ * doesn't apply. Instead, pass options directly to the APIs.
+ *
+ * All configuration options: https://remotion.dev/docs/config
+ */
+
+import { Config } from "@remotion/cli/config";
+import { enableTailwind } from '@remotion/tailwind-v4';
+
+Config.setRspack(true);
+Config.setVideoImageFormat("jpeg");
+Config.setOverwriteOutput(true);
+Config.overrideBundlerConfig(enableTailwind);