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/zh-TW/index.md

@@ -0,0 +1,11 @@
+---
+layout: page
+title: "SnapOtter Docs"
+description: "開源、自我託管的檔案處理基礎架構。透過 UI、REST API 與管線，跨影像、影片、音訊、PDF 與文件進行轉換、壓縮、OCR、轉錄，並執行本機 AI。用一道 Docker 指令自我託管。你的檔案絕不離開你的伺服器。"
+sidebar: false
+i18n_source_hash: 449a5b93eef1
+i18n_provenance: machine
+i18n_output_hash: cadd2b10c29c
+---
+
+<DocsHome />