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/tool-anlegen.en.md

@@ -0,0 +1,46 @@
+
+# Create a tool
+
+To add a new tool to the catalog, click **Add tool**
+(`/tools/new`). Creating a tool requires an account — without being signed in
+a notice with a login button appears.
+
+## Form fields
+
+| Field | Required | Notes |
+| --- | --- | --- |
+| **Name** | Yes | At least 2 characters |
+| **Category** | Yes | Dropdown; new categories can be created directly |
+| **Website URL** | No | Valid URL (e.g. `https://...`) |
+| **Icon / Logo URL** | No | Valid URL; preview is shown live |
+| **Description** | Yes | At least 10 characters; describe what the tool does |
+| **Features** | No | Dynamic list with autocomplete (max. 6) |
+| **Tags** | No | Dynamic list with autocomplete |
+
+Next to each field, the **? icon** takes you directly to the corresponding
+field description in the [data model reference](/docs/reference/schemas/toolinput).
+
+### Category
+
+- Type to search for existing categories.
+- Select **+ Create "..."** to create a new category.
+
+### Features & tags
+
+- **Add feature** / **Add tag** appends a new row.
+- The input fields suggest existing features/tags
+  (autocomplete, max. 6 suggestions).
+- Use the **×** button to remove individual rows.
+- Features and tags help with filtering and finding tools again.
+
+## Save
+
+Click **Add tool**. After successful creation you will be redirected to the
+detail page of the new tool.
+
+## API
+
+- [`POST /tools`](/docs/reference/endpoints/tools#createTool) — create a tool
+- [`GET /categories`](/docs/reference/endpoints/tools#listCategories) — categories
+- [`GET /features/all`](/docs/reference/endpoints/tools#listAllFeatures) — features
+- [`GET /tags/all`](/docs/reference/endpoints/tools#listAllTags) — tags