Remove IPA:DE option — no German IPA dictionary available

Our IPA system only has English dictionaries (Britfone MIT, eng_to_ipa
MIT). The "IPA: nur DE" option was useless at best and misleading.
Removed from dropdown, type definition, and API validation.

Syllable DE mode stays — pyphen has a German hyphenation dictionary.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-lehrer/components/grid-editor/GridToolbar.tsx

@@ -22,7 +22,6 @@ interface GridToolbarProps {
 const IPA_LABELS: Record<IpaMode, string> = {
   auto: 'IPA: Auto',
   en: 'IPA: nur EN',
-  de: 'IPA: nur DE',
   all: 'IPA: Alle',
   none: 'IPA: Aus',
 }

admin-lehrer/components/grid-editor/useGridEditor.ts

@@ -14,7 +14,7 @@ export interface GridEditorState {
   selectedZone: number | null
 }
 
-export type IpaMode = 'auto' | 'all' | 'de' | 'en' | 'none'
+export type IpaMode = 'auto' | 'all' | 'en' | 'none'
 export type SyllableMode = 'auto' | 'all' | 'de' | 'en' | 'none'
 
 export function useGridEditor(sessionId: string | null) {

klausur-service/backend/grid_editor_api.py

@@ -1593,7 +1593,7 @@ async def _build_grid_core(
 @router.post("/sessions/{session_id}/build-grid")
 async def build_grid(
     session_id: str,
-    ipa_mode: str = Query("auto", pattern="^(auto|all|de|en|none)$"),
+    ipa_mode: str = Query("auto", pattern="^(auto|all|en|none)$"),
     syllable_mode: str = Query("auto", pattern="^(auto|all|de|en|none)$"),
 ):
     """Build a structured, zone-aware grid from existing Kombi word results.