Add language-specific IPA and syllable modes (de/en)

Extend ipa_mode and syllable_mode toggles with language options:
- auto: smart detection (default)
- en: only English headword column
- de: only German definition columns
- all: all content columns
- none: skip entirely

Also improve English column auto-detection: use garbled IPA patterns
(apostrophes, colons) in addition to bracket patterns. This correctly
identifies English dictionary pages where OCR produces garbled ASCII
instead of bracket IPA.

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

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

@@ -14,8 +14,8 @@ export interface GridEditorState {
   selectedZone: number | null
 }
 
-export type IpaMode = 'auto' | 'all' | 'none'
-export type SyllableMode = 'auto' | 'all' | 'none'
+export type IpaMode = 'auto' | 'all' | 'de' | 'en' | 'none'
+export type SyllableMode = 'auto' | 'all' | 'de' | 'en' | 'none'
 
 export function useGridEditor(sessionId: string | null) {
   const [grid, setGrid] = useState<StructuredGrid | null>(null)