feat(docs-i18n): translate all documentation into 20 languages

All 181 docs markdown files translated into 20 languages (apps/docs/<locale>/**). Companion to the i18n code PR; admin-merged because the file count exceeds GitHub's per-PR CI trigger limit. Validated by pnpm i18n:check (all surfaces, 0 stale/missing) and a clean all-locale docs build.

apps/docs/id/tools/audio/convert-audio.md

@@ -0,0 +1,49 @@
+---
+description: "Konversi audio antara format MP3, WAV, OGG, FLAC, dan M4A."
+i18n_source_hash: fd02c059e6a9
+i18n_provenance: human
+i18n_output_hash: 06454316167e
+---
+
+# Convert Audio {#convert-audio}
+
+Konversi file audio antara format umum termasuk MP3, WAV, OGG, FLAC, dan M4A, dengan bitrate output yang dapat dikonfigurasi.
+
+## API Endpoint {#api-endpoint}
+
+`POST /api/v1/tools/audio/convert-audio`
+
+Menerima data formulir multipart dengan file audio dan bidang JSON `settings`.
+
+## Parameter {#parameters}
+
+| Parameter | Tipe | Wajib | Bawaan | Deskripsi |
+|-----------|------|----------|---------|-------------|
+| format | string | Tidak | `"mp3"` | Format output: `mp3`, `wav`, `ogg`, `flac`, `m4a` |
+| bitrateKbps | integer | Tidak | `192` | Bitrate output dalam kbps (32 hingga 320) |
+
+## Contoh Permintaan {#example-request}
+
+```bash
+curl -X POST http://localhost:1349/api/v1/tools/audio/convert-audio \
+  -H "Authorization: Bearer si_your-api-key" \
+  -F "file=@audio.mp3" \
+  -F 'settings={"format": "flac", "bitrateKbps": 256}'
+```
+
+## Contoh Respons {#example-response}
+
+```json
+{
+  "jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
+  "downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/audio.flac",
+  "originalSize": 4500000,
+  "processedSize": 8200000
+}
+```
+
+## Catatan {#notes}
+
+- Format input yang didukung meliputi MP3, WAV, OGG, FLAC, AAC, M4A, WMA, AIFF, dan OPUS.
+- Bitrate hanya berlaku untuk format lossy (MP3, OGG, M4A). Format lossless seperti WAV dan FLAC mengabaikan pengaturan ini.
+- Nama file output mempertahankan nama asli dengan ekstensi baru.