chore(engine): pin 0.29.0 and leave the hint-length rule to the engine

.github/ownership.json

@@ -51,7 +51,6 @@
     "tests/test_export_quiz_pdf.py": "template",
     "tests/test_from_cards_pairs_gate.py": "template",
     "tests/test_generate_exercises.py": "template",
-    "tests/test_hint_length_rule.py": "template",
     "tests/test_mc_only_exemption.py": "template",
     "tests/test_quality_state.py": "template",
     "tests/test_shape_parity.py": "template",
@@ -96,8 +95,6 @@
     "tests/test_export_set.py": "repo",
     "tests/test_hub_generated_sets.py": "repo",
     "tests/test_ki_einsteiger_ai_validated.py": "repo",
-    "tests/test_known_domain.py": "repo",
-    "tests/test_prompt_duplication_rule.py": "repo",
     "tests/test_readme_set_table.py": "repo",
     "schema/content-manifest.schema.json": "engine",
     "schema/lesson.schema.json": "engine",

schema/engine-version.txt

@@ -1 +1 @@
-0.28.0
+0.29.0

scripts/validate_content.py

@@ -56,45 +56,10 @@
 
 ISO_639_1 = re.compile(r"^[a-z]{2}$")
 
-# Answer-length statements in exercise/blank hints (adaptive-learner-content#100).
-# The app shows the answer's length automatically (the system hint), so an
-# authored hint stating a letter/character count ("Vier Buchstaben.") is
-# redundant at best and contradicts the system hint when it is wrong. Card
-# hints are NOT covered: a character count there can be legitimate teaching
-# content (e.g. explaining that ``s[0:3]`` yields 3 characters). Compounds
-# like "Leerzeichen" do not match (no word boundary inside the compound),
-# so indentation advice passes.
-#
-# The count words also cover the English number words (one to twelve;
-# hyphenated adjectives like "five-letter" match via the ``[-\s]+`` joiner)
-# and the single-character adjectives ("ein einzelnes Zeichen", "a single
-# character" state answer length 1), adaptive-learner-content#102. Compounds
-# still pass: "Ein einzelner Kleinbuchstabe" conveys CASE, which the system
-# hint does not show, and "the letter she wrote" has no count word before the
-# noun.
-_HINT_COUNT_WORDS = (
-    r"\d+|ein(?:e[nmrs]?)?|zwei|drei|vier|f(?:ü|ue)nf|sechs|sieben|acht|neun"
-    r"|zehn|elf|zw(?:ö|oe)lf"
-    r"|one|two|three|four|five|six|seven|eight|nine|ten|eleven|twelve"
-    r"|einzeln\w*|single"
-)
-HINT_LENGTH_PATTERN = re.compile(
-    rf"\b(?:{_HINT_COUNT_WORDS})[-\s]+(?:buchstaben?|zeichen|letters?|characters?)\b"
-    r"|\w*buchstabig",
-    re.IGNORECASE,
-)
-
-
-def hint_states_answer_length(hint: object) -> bool:
-    """True when an authored hint states the answer's letter/character count.
-
-    Matches a digit, a German or English number word, or a single-character
-    adjective ("einzeln..."/"single") followed by "Buchstabe(n)"/"Zeichen"/
-    "letter(s)"/"character(s)" (plus the "-buchstabig" adjectives). Applied to
-    exercise-level and blank-level hints only - see the note on
-    ``HINT_LENGTH_PATTERN``.
-    """
-    return isinstance(hint, str) and bool(HINT_LENGTH_PATTERN.search(hint))
+# Answer-length statements in hints are the engine's rule: W-HINT-LENGTH
+# (learn-content-engine#186, since 0.29.0) checks exercise and blank hints with
+# the forms this validator used to check, and reports them in the engine gate's
+# warning step. Content rules belong to the engine, not to a second copy here.
 
 # Scripts we can distinguish from Latin (mirror the TS validator).
 SCRIPT_RANGES = {
@@ -285,18 +250,6 @@ def validate_lesson_quality(lesson: dict, source: str, label: str, errors: list[
 
     for ex in exercises:
         eid = ex.get("id", "?")
-        if hint_states_answer_length(ex.get("hint")):
-            errors.append(
-                f"{label}: exercise '{eid}' hint states a letter/character count "
-                "(redundant to the app's automatic length hint) - use a content hint"
-            )
-        for blank_index, blank in enumerate(ex.get("blanks") or []):
-            if isinstance(blank, dict) and hint_states_answer_length(blank.get("hint")):
-                errors.append(
-                    f"{label}: exercise '{eid}' blanks[{blank_index}] hint states a "
-                    "letter/character count (redundant to the app's automatic "
-                    "length hint) - use a content hint"
-                )
         if ex.get("type") == "free_text":
             if len(ex.get("accept") or []) < MIN_FREE_TEXT_ACCEPTS:
                 errors.append(f"{label}: free_text '{eid}' needs >= {MIN_FREE_TEXT_ACCEPTS} accepts")