feat(docs): standalone docs page, Hilfe nav entry, rewritten user guide

- docs route renders without the app shell (own header, back-to-app link,
  theme toggle)
- nav entry renamed to Hilfe (de) / Help (en)
- reference links now case-insensitive (schema/tag slugs)
- handbook rewritten as 17-page user guide with links into the API reference
- release notes v0.8.1 added

artifacts/toolrate/src/i18n/locales/de.json

@@ -12,7 +12,7 @@
     "trash": "Papierkorb",
     "admin": "Admin",
     "redundancy": "Redundanz",
-    "docs": "Doku",
+    "docs": "Hilfe",
     "search": "Tools suchen…"
   },
   "auth": {
@@ -198,7 +198,18 @@
     "reference": "API-Referenz",
     "referenceIntro": "Automatisch aus der OpenAPI-Spezifikation generiert — alle Endpunkte und Datenfelder der aktuellen Version.",
     "onThisPage": "Auf dieser Seite",
-    "searchPlaceholder": "Doku durchsuchen…"
+    "searchPlaceholder": "Doku durchsuchen…",
+    "backToApp": "Zur App",
+    "field": "Feld",
+    "type": "Typ",
+    "required": "Pflicht",
+    "description": "Beschreibung",
+    "status": "Status",
+    "schema": "Schema",
+    "parameter": "Parameter",
+    "noResults": "Keine Treffer",
+    "fields": "Felder",
+    "fieldHelpHint": "Hinweis: Formular-Felder verlinken per ?-Icon direkt zu den jeweiligen Zeilen dieser Tabelle."
   },
   "command": {
     "navigate": "Navigation",