docs: cut to v0.9.0 with unified .de/.en naming

- Remove all prior release notes and version snapshots (v0.6.0-v0.8.6)
- Rename handbook to *.de.md; keep *.en.md
- New release notes v0.9.0.de.md/.en.md with v0.9.0 snapshot
- generate-docs.mjs: .de/.en convention incl. search index and en-fallback
- docs.tsx: release fallback now uses version.de.md
- Wording: neutral tagline, anonymous user, no gender forms
- Add docs/examples/import-tools.yaml and link from administration docs

docs/releases/v0.9.0/handbook/konto.en.md

@@ -0,0 +1,52 @@
+
+# Login & Account
+
+## Logging in
+
+Click **Login** at the bottom left of the sidebar. Depending on the
+configuration of the instance:
+
+- **Local accounts:** enter username and password. The accounts are created
+  by an admin (see [Administration](/docs/handbook/administration)).
+- **OIDC (SSO):** you are redirected to the configured identity provider and
+  log in there.
+
+The active mode is available at the endpoint
+[`GET /auth/mode`](/docs/reference/endpoints/auth#getAuthMode).
+
+> You can reach the login page directly at `/login`. After a successful
+> login you are redirected back to the page you originally requested.
+
+## User profile
+
+You can see your profile (avatar, name, email, plan) at the bottom left in
+the user menu. There you have the following actions available:
+
+- **Watchlist** — your saved tools (only with the corresponding plan).
+- **Trash** — restorable, deleted tools (Premium/Enterprise).
+- **Change password** — directly in toolr for local accounts; for OIDC
+  accounts, password management is offered in the identity provider.
+- **Logout** — ends your session.
+
+## Changing your password (local account)
+
+1. Open the user menu at the bottom left.
+2. Select **Change password**.
+3. Enter the **current** and a **new** password (min. 6 characters) and
+   confirm it.
+4. Save — the password takes effect immediately.
+
+API reference: [`POST /auth/me/password`](/docs/reference/endpoints/auth#changeMyPassword).
+
+## Display settings
+
+Using the buttons at the top right you can:
+
+- switch the **language** (German / English),
+- toggle the **theme** (Light / Dark / System),
+- adjust the **list view** and **density** in the Browse tools section
+  (see [Finding & browsing tools](/docs/handbook/tools-finden)).
+
+Your preferences (incl. watchlist) are saved at the endpoint
+[`GET /auth/me/preferences`](/docs/reference/endpoints/auth#getMePreferences)
+and updated via [`PUT /auth/me/preferences`](/docs/reference/endpoints/auth#updateMePreferences).