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

src/Composition.tsx

@@ -0,0 +1,25 @@
+import { CalculateMetadataFunction, Composition } from "remotion";
+
+type Props = {};
+
+const calculateMetadata: CalculateMetadataFunction<Props> = () => {
+  return {};
+};
+
+export const MyComposition = () => {
+  return (
+    <Composition
+      id="MyComp"
+      component={MyComponent}
+      durationInFrames={60}
+      fps={30}
+      width={1280}
+      height={720}
+      calculateMetadata={calculateMetadata}
+    />
+  );
+};
+
+export const MyComponent: React.FC<Props> = () => {
+  return null;
+};

src/Root.tsx

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+import "./index.css";
+import { MyComposition } from "./Composition";
+
+export const RemotionRoot: React.FC = () => {
+  return (
+    <>
+      <MyComposition />
+    </>
+  );
+};

src/index.css

@@ -0,0 +1 @@
+@import "tailwindcss";

src/index.ts

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+import { registerRoot } from "remotion";
+import { RemotionRoot } from "./Root";
+
+registerRoot(RemotionRoot);

src/lrc2srt.ts

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+#!/usr/bin/env node
+// lrc→srt converter — minimal, no external dependencies
+//
+// Usage:
+//   node lrc2srt.ts <input.lrc> [output.srt]
+//
+// If output is omitted, writes to stdout.
+
+import * as fs from "fs";
+import * as path from "path";
+
+function lrcTimeToSeconds(line: string): number | null {
+  const match = line.match(/\[(\d{1,2}):(\d{2})\.(\d{2,3})\]/);
+  if (!match) return null;
+
+  const minutes = parseInt(match[1], 10);
+  const seconds = parseInt(match[2], 10);
+  const centis = match[3].padEnd(3, "0").substring(0, 3);
+  const ms = parseInt(centis, 10);
+
+  return minutes * 60 + seconds + ms / 1000;
+}
+
+function secondsToSrtTime(t: number): string {
+  const hours = Math.floor(t / 3600);
+  const minutes = Math.floor((t % 3600) / 60);
+  const secs = Math.floor(t % 60);
+  const ms = Math.round((t - Math.floor(t)) * 1000);
+
+  return `${String(hours).padStart(2, "0")}:${String(minutes).padStart(2, "0")}:${String(secs).padStart(2, "0")},${String(ms).padStart(3, "0")}`;
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  if (args.length < 1) {
+    console.error("Usage: lrc2srt.ts <input.lrc> [output.srt]");
+    process.exit(1);
+  }
+
+  const input = fs.readFileSync(args[0], "utf-8");
+  const lines = input.split(/\r?\n/);
+  const entries: { start: number; end: number; text: string }[] = [];
+  let currentStart: number | null = null;
+  let currentText: string | null = null;
+
+  for (const raw of lines) {
+    const trimmed = raw.trim();
+    if (!trimmed) continue;
+
+    const timeMatch = trimmed.match(/\[(\d{1,2}):(\d{2})\.(\d{2,3})\]/);
+    const text = trimmed.replace(/\[\d{1,2}:\d{2}\.\d{2,3}\]/g, "").trim();
+
+    if (timeMatch && !currentStart) {
+      currentStart = lrcTimeToSeconds(raw);
+      currentText = text;
+    } else if (currentStart && currentText) {
+      // If there's a time tag, the current entry ends here
+      entries.push({ start: currentStart, end: currentStart + 1, text: currentText });
+      currentStart = lrcTimeToSeconds(raw);
+      currentText = text;
+    } else if (currentStart && !currentText) {
+      currentText = text;
+    } else if (!currentStart) {
+      // line without time tag, skip
+    }
+  }
+
+  if (currentStart && currentText) {
+    entries.push({ start: currentStart, end: currentStart + 1, text: currentText });
+  }
+
+  // Fix end times: each entry ends when the next one starts
+  for (let i = 0; i < entries.length; i++) {
+    if (i + 1 < entries.length) {
+      entries[i].end = entries[i + 1].start;
+    } else {
+      entries[i].end = entries[i].start + 5; // default 5s for last line
+    }
+  }
+
+  const srtBlocks = entries.map((e, idx) => {
+    return `${idx + 1}\n${secondsToSrtTime(e.start)} --> ${secondsToSrtTime(e.end)}\n${e.text}`;
+  });
+
+  const output = srtBlocks.join("\n\n") + "\n";
+  const outPath = args[1];
+  if (outPath) {
+    fs.writeFileSync(outPath, output, "utf-8");
+  } else {
+    process.stdout.write(output);
+  }
+}
+
+main();