Add IPA and syllable mode toggles, fix false IPA on German documents

Backend: Remove en_col_type fallback heuristic (longest avg text) that
incorrectly identified German columns as English. IPA now only applied
when OCR bracket patterns are actually found. Add ipa_mode (auto/all/none)
and syllable_mode (auto/all/none) query params to build-grid API.

Frontend: Add IPA and Silben dropdown selects to GridToolbar. Modes
are passed as query params on rebuild. Auto = current smart detection,
All = force for all words, Aus = skip entirely.

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

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

@@ -14,6 +14,9 @@ export interface GridEditorState {
   selectedZone: number | null
 }
 
+export type IpaMode = 'auto' | 'all' | 'none'
+export type SyllableMode = 'auto' | 'all' | 'none'
+
 export function useGridEditor(sessionId: string | null) {
   const [grid, setGrid] = useState<StructuredGrid | null>(null)
   const [loading, setLoading] = useState(false)
@@ -22,6 +25,8 @@ export function useGridEditor(sessionId: string | null) {
   const [dirty, setDirty] = useState(false)
   const [selectedCell, setSelectedCell] = useState<string | null>(null)
   const [selectedZone, setSelectedZone] = useState<number | null>(null)
+  const [ipaMode, setIpaMode] = useState<IpaMode>('auto')
+  const [syllableMode, setSyllableMode] = useState<SyllableMode>('auto')
 
   // Undo/redo stacks store serialized zone arrays
   const undoStack = useRef<string[]>([])
@@ -44,8 +49,11 @@ export function useGridEditor(sessionId: string | null) {
     setLoading(true)
     setError(null)
     try {
+      const params = new URLSearchParams()
+      params.set('ipa_mode', ipaMode)
+      params.set('syllable_mode', syllableMode)
       const res = await fetch(
-        `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/build-grid`,
+        `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/build-grid?${params}`,
         { method: 'POST' },
       )
       if (!res.ok) {
@@ -62,7 +70,7 @@ export function useGridEditor(sessionId: string | null) {
     } finally {
       setLoading(false)
     }
-  }, [sessionId])
+  }, [sessionId, ipaMode, syllableMode])
 
   const loadGrid = useCallback(async () => {
     if (!sessionId) return
@@ -915,5 +923,9 @@ export function useGridEditor(sessionId: string | null) {
     toggleSelectedBold,
     autoCorrectColumnPatterns,
     setCellColor,
+    ipaMode,
+    setIpaMode,
+    syllableMode,
+    setSyllableMode,
   }
 }