Fix hyphen-join: preserve next row + skip valid hyphenations

Two bugs fixed:
- Apply no longer removes the continuation word from the next row.
  "künden" stays in row 31 — only the current row is repaired
  ("ve" → "ver-"). The original line-break layout is preserved.
- Analysis now skips words that already end with "-" when the direct
  join with the next row is a known word (valid hyphenation, not an error).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

klausur-service/backend/cv_gutter_repair.py

@@ -400,8 +400,17 @@ def analyse_grid_for_gutter_repair(
                 next_words = next_text.split()
                 if next_words:
                     first_next = next_words[0]
+                    first_next_clean = _TRAILING_PUNCT_RE.sub('', first_next)
                     first_alpha = next((c for c in first_next if c.isalpha()), "")
 
+                    # If the word already ends with "-" and the direct join
+                    # (no missing chars) is a known word, this is a VALID
+                    # hyphenation — not a gutter error. Skip it.
+                    if ends_with_hyphen and first_next_clean:
+                        direct = last_word_clean.rstrip("-") + first_next_clean
+                        if _is_known(direct):
+                            continue
+
                     # Continuation likely if:
                     # - explicit hyphen, OR
                     # - next row starts lowercase (= not a new entry)
@@ -557,13 +566,16 @@ def apply_gutter_suggestions(
             # The first display part is what goes in the current row
             first_part = display_parts[0] if display_parts else ""
 
-            # Replace the last word in current cell
+            # Replace the last word in current cell with the restored form.
+            # The next row is NOT modified — "künden" stays in its row
+            # because the original book layout has it there. We only fix
+            # the truncated word in the current row (e.g. "ve" → "ver-").
             idx = old_text.rfind(original_word)
             if idx >= 0:
                 new_text = old_text[:idx] + first_part + old_text[idx + len(original_word):]
                 target_cell["text"] = new_text
                 changes.append({
-                    "type": "hyphen_join_current",
+                    "type": "hyphen_join",
                     "zone_index": zi,
                     "row_index": ri,
                     "col_index": ci,
@@ -573,30 +585,6 @@ def apply_gutter_suggestions(
                     "joined_word": joined,
                 })
 
-            # Next row: remove the first word (it's now joined into current row)
-            if next_ri >= 0:
-                next_cell = None
-                for cell in zone_cells:
-                    if cell.get("row_index") == next_ri and cell.get("col_index") == ci:
-                        next_cell = cell
-                        break
-
-                if next_cell:
-                    next_old = next_cell.get("text", "")
-                    next_words = next_old.split()
-                    if next_words:
-                        next_new = " ".join(next_words[1:])
-                        next_cell["text"] = next_new
-                        changes.append({
-                            "type": "hyphen_join_next",
-                            "zone_index": zi,
-                            "row_index": next_ri,
-                            "col_index": ci,
-                            "cell_id": next_cell.get("cell_id", ""),
-                            "old_text": next_old,
-                            "new_text": next_new,
-                        })
-
     logger.info("Gutter repair applied: %d/%d suggestions", len(changes), len(accepted_suggestions))
 
     return {

klausur-service/backend/tests/test_gutter_repair.py

@@ -310,8 +310,8 @@ class TestApplySuggestions:
         assert result["applied_count"] == 1
         # Current row: "ve" replaced with "ver-"
         assert grid["zones"][0]["cells"][0]["text"] == "ver-"
-        # Next row: "künden" removed, "und" remains
-        assert grid["zones"][0]["cells"][1]["text"] == "und"
+        # Next row: UNCHANGED — "künden" stays in its original row
+        assert grid["zones"][0]["cells"][1]["text"] == "künden und"
 
     def test_apply_nothing_when_no_accepted(self):
         grid = _make_grid([])