i18n: add mechanism for blocking new terms

.pre-commit-config.yaml

@@ -28,6 +28,14 @@ repos:
         language: system
         files: ^quickshell/(Modules/Settings/.*\.qml|Modals/Settings/SettingsSidebar\.qml|translations/extract_settings_index\.py)$
         pass_filenames: false
+  - repo: local
+    hooks:
+      - id: i18n-term-freeze
+        name: i18n term freeze (no new I18n.tr/qsTr terms)
+        entry: python3 quickshell/translations/check_term_freeze.py
+        language: system
+        files: ^quickshell/(.*\.qml|translations/(term_freeze\.json|check_term_freeze\.py|extract_translations\.py))$
+        pass_filenames: false
   - repo: local
     hooks:
       - id: no-console-in-qml

quickshell/translations/check_term_freeze.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+"""Enforce the i18n term freeze.
+
+While term_freeze.json exists, any I18n.tr()/qsTr() term not in it fails the check.
+Existing terms may be reused or moved freely.
+
+  --update   re-snapshot the current terms into term_freeze.json
+  (delete term_freeze.json to lift the freeze)
+"""
+import json
+import sys
+from pathlib import Path
+
+from extract_translations import extract_qstr_strings
+
+SCRIPT_DIR = Path(__file__).parent
+ROOT_DIR = SCRIPT_DIR.parent
+FREEZE_FILE = SCRIPT_DIR / 'term_freeze.json'
+
+
+def main():
+    if '--update' in sys.argv:
+        translations = extract_qstr_strings(ROOT_DIR)
+        FREEZE_FILE.write_text(json.dumps(sorted(translations), indent=2, ensure_ascii=False) + '\n', encoding='utf-8')
+        print(f"Froze {len(translations)} terms to {FREEZE_FILE}")
+        return 0
+
+    if not FREEZE_FILE.exists():
+        print("i18n term freeze inactive (term_freeze.json not present)")
+        return 0
+
+    frozen = set(json.loads(FREEZE_FILE.read_text(encoding='utf-8')))
+    translations = extract_qstr_strings(ROOT_DIR)
+    new_terms = sorted(term for term in translations if term not in frozen)
+    if not new_terms:
+        return 0
+
+    print(f"i18n term freeze: {len(new_terms)} new term(s) introduced:", file=sys.stderr)
+    for term in new_terms:
+        print(f'\n  "{term}"', file=sys.stderr)
+        for occ in translations[term]['occurrences']:
+            print(f"    quickshell/{occ['file']}:{occ['line']}", file=sys.stderr)
+    print("\nReuse an existing term instead. To intentionally allow new terms, run", file=sys.stderr)
+    print("  python3 quickshell/translations/check_term_freeze.py --update", file=sys.stderr)
+    print("and stage term_freeze.json. Delete term_freeze.json to lift the freeze entirely.", file=sys.stderr)
+    return 1
+
+
+if __name__ == '__main__':
+    sys.exit(main())