feat(i18n): full app + docs localization (de/en)

- translate remaining pages/components (admin, analytics, redundancy,
  trash, compare, browse, watchlist, admin tools tab, category combobox,
  theme toggle, tool preview card, tool-new/edit) to t() calls
- locales: 453 keys each, parity verified
- docs: bilingual handbook + release notes via *.en.md variants,
  language-aware docs.tsx (markdown paths, nav titles, search index),
  LanguageSwitcher in docs header
- generate-docs: emit per-locale handbook/release/search output,
  localized index.json fields (fileEn/titleEn), en-aware snapshots

docs/releases/v0.8.2.en.md

@@ -0,0 +1,35 @@
+# v0.8.2 — Release Notes
+
+**Date:** 2026-08-04 · **Tag:** [`v0.8.2`](https://git.kubebase.de/admin/tool-evaluator/releases/tag/v0.8.2)
+
+## Fixes & improvements
+
+- **Mobile navigation in the docs**: The left navigation bar (manual,
+  endpoints, schemas) was completely hidden below `lg` (1024px).
+  There is now a menu button in the header that opens a side
+  navigation drawer with the same content — on small screens
+  the docs remain fully navigable.
+- **Version dropdown shows the selected version**: When switching to a
+  different release (`/docs/releases/vX.Y.Z`), the dropdown wrongly stayed on
+  "current". The displayed version is now also derived from the releases route.
+
+## API changes
+
+- No changes to the API.
+
+## Operations / upgrade
+
+- **Env vars:** unchanged.
+- **Migration:** none.
+- **Breaking changes:** none.
+
+## Known limitations
+
+- Manual & reference apply to the current version; older versions show
+  their release notes and a reference snapshot, if generated at release time
+  (`node scripts/src/generate-docs.mjs --snapshot vX.Y.Z`).
+
+## Links
+
+- Commit: [`33cf261`](https://git.kubebase.de/admin/tool-evaluator/commit/33cf261)
+- Tag: [`v0.8.2`](https://git.kubebase.de/admin/tool-evaluator/releases/tag/v0.8.2)