feat: bundle yt-dlp and ffmpeg Linux binaries in bin/

Adds precompiled Linux x86_64 binaries for yt-dlp and ffmpeg under bin/.
The processor resolves yt-dlp from bin/ when present, falling back to PATH.
ffmpeg is passed via --ffmpeg-location so yt-dlp uses the bundled binary on o2switch.
BIN_DIR is configurable via env var.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config/app.config.ts

@@ -1,3 +1,5 @@
+import path from 'path'
+
 export const config = {
   DOWNLOAD_LINK_TTL_HOURS: 24,
   WORKER_CONCURRENCY: 3,
@@ -5,4 +7,5 @@ export const config = {
   STORAGE_PATH: process.env.STORAGE_PATH ?? '',
   RATE_LIMIT_MAX: 5,
   RATE_LIMIT_WINDOW_MS: 3_600_000,
+  BIN_DIR: process.env.BIN_DIR ?? path.join(process.cwd(), 'bin'),
 } as const

src/lib/ytdlp.ts

@@ -1,3 +1,4 @@
+import { existsSync } from 'fs'
 import path from 'path'
 import { config } from '../../config/app.config'
 
@@ -16,6 +17,11 @@ export function buildYtdlpArgs(params: YtdlpParams): string[] {
 
   const args: string[] = ['--no-playlist', '-o', outputTemplate]
 
+  const ffmpegBin = path.join(config.BIN_DIR, 'ffmpeg')
+  if (existsSync(ffmpegBin)) {
+    args.push('--ffmpeg-location', ffmpegBin)
+  }
+
   if (quality !== 'best') {
     const height = quality.replace('p', '')
     args.push('-f', `${format}[height<=?${height}]+bestaudio/best[height<=?${height}]`)

worker/processor.ts

@@ -1,11 +1,16 @@
 import { spawn } from 'child_process'
-import { readdirSync, statSync } from 'fs'
+import { existsSync, readdirSync, statSync } from 'fs'
 import path from 'path'
 import { prisma } from '@/lib/prisma'
 import { buildYtdlpArgs } from '@/lib/ytdlp'
 import { createToken } from '@/lib/token'
 import { config } from '../config/app.config'
 
+function resolveYtdlpBin(): string {
+  const local = path.join(config.BIN_DIR, 'yt-dlp')
+  return existsSync(local) ? local : 'yt-dlp'
+}
+
 export async function processDownload(downloadId: string): Promise<void> {
   const download = await prisma.download.findUnique({ where: { id: downloadId } })
   if (!download) return
@@ -22,7 +27,7 @@ export async function processDownload(downloadId: string): Promise<void> {
   let stderr = ''
 
   await new Promise<void>((resolve) => {
-    const proc = spawn('yt-dlp', args)
+    const proc = spawn(resolveYtdlpBin(), args)
     proc.stderr.on('data', (chunk: Buffer) => { stderr += chunk.toString() })
 
     proc.on('close', async (code) => {