Remove IPA continuation rows and support hyphenated word lookup

- grid_editor_api: After IPA correction, detect rows containing only
  garbled phonetics in the English column (no German translation, no
  IPA brackets inserted). These are wrap-around lines where printed
  IPA extends to the line below the headword. Remove them since the
  headword row already has correct IPA.
- cv_ocr_engines: _insert_missing_ipa now tries dehyphenated form
  as fallback (e.g. "second-hand" → "secondhand") for dictionary
  lookup, fixing IPA insertion for compound words.

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

klausur-service/backend/grid_editor_api.py

@@ -1196,6 +1196,50 @@ async def build_grid(session_id: str):
             if orig:
                 cell["col_type"] = orig
 
+        # 5d. Remove IPA continuation rows — rows where the printed
+        # phonetic transcription wraps to a line below the headword.
+        # These rows have text only in the English column (+ margin
+        # noise) and fix_cell_phonetics did NOT insert IPA brackets
+        # (because there's no real English word to look up).
+        ipa_cont_rows: set = set()
+        for z in zones_data:
+            for row in z.get("rows", []):
+                ri = row["index"]
+                row_cells = [
+                    c for c in z.get("cells", [])
+                    if c.get("row_index") == ri
+                ]
+                en_cells = [
+                    c for c in row_cells
+                    if c.get("col_type") == en_col_type
+                ]
+                # Other cells with ≥3 chars (ignore margin noise)
+                other_cells = [
+                    c for c in row_cells
+                    if c.get("col_type") != en_col_type
+                    and len((c.get("text") or "").strip()) >= 3
+                ]
+                if en_cells and not other_cells:
+                    en_text = en_cells[0].get("text", "")
+                    # No IPA brackets → phonetics not recognized →
+                    # this is a garbled IPA continuation row
+                    if "[" not in en_text:
+                        ipa_cont_rows.add(ri)
+        if ipa_cont_rows:
+            for z in zones_data:
+                z["rows"] = [
+                    r for r in z.get("rows", [])
+                    if r["index"] not in ipa_cont_rows
+                ]
+                z["cells"] = [
+                    c for c in z.get("cells", [])
+                    if c.get("row_index") not in ipa_cont_rows
+                ]
+            logger.info(
+                "removed %d IPA continuation rows: %s",
+                len(ipa_cont_rows), sorted(ipa_cont_rows),
+            )
+
     duration = time.time() - t0
 
     # 6. Build result