fix(skill-cache): purge compacts for mixed-case skill names on invalidation

invalidate_for_path built the compact-purge suffix from the un-lowercased
meta.skill_name, but _compact_file_id (the writer) lowercases the safe-name
segment. For a mixed-case namespaced skill such as userSettings:brainstorming,
the on-disk compact is named ...-usersettings_brainstormingn-compact while the
purge suffix was ...-userSettings_brainstormingn-compact, so the endswith match
missed and the stale compact survived a skill edit — a later --compact recall
served pre-edit content. Lowercase the safe name in the purger to mirror the
writer exactly.

Author: Zelys-DFKH

src/token_goat/skill_cache.py

@@ -999,7 +999,12 @@ def invalidate_for_path(file_path: str) -> int:
             continue
         # Match found: collect the compact suffix pattern BEFORE removing files
         # so the suffix is available even after the body .txt is deleted.
-        safe_name = meta.skill_name.replace(":", "_")
+        # Must mirror _compact_file_id exactly — it lowercases the safe name, so
+        # a mixed-case skill name (e.g. "userSettings:brainstorming") writes a
+        # compact file as "...-usersettings_brainstormingn-compact". Without the
+        # same .lower() here the purge suffix never matches and the stale compact
+        # survives a skill edit.
+        safe_name = meta.skill_name.lower().replace(":", "_")
         if ":" in meta.skill_name:
             safe_name += "n"
         compact_suffixes.add(f"-{safe_name}-compact")

tests/test_skill_worker_invalidation.py

@@ -130,6 +130,33 @@ def test_compact_removal_with_namespaced_skill(self, tmp_data_dir):
         compact_after = [f for f in cache_dir.iterdir() if f.name.endswith("-compact")]
         assert len(compact_after) == 0
 
+    def test_compact_removal_with_mixed_case_skill(self, tmp_data_dir):
+        """Compact removal works for mixed-case namespaced names (regression).
+
+        _compact_file_id lowercases the safe-name segment, so a skill named
+        "userSettings:brainstorming" writes its compact as
+        "...-usersettings_brainstormingn-compact". invalidate_for_path previously
+        built the purge suffix from the un-lowercased meta.skill_name, so the
+        suffix ("...-userSettings_brainstormingn-compact") never matched the
+        on-disk file and the stale compact survived the edit. Fails pre-fix
+        (compact_after == 1), passes post-fix (compact_after == 0).
+        """
+        source = "/plugins/core/skills/brainstorming/SKILL.md"
+        meta = skill_cache.store_output(
+            "sess_mc", "userSettings:brainstorming", "body " * 200, source_path=source
+        )
+        assert meta is not None
+        skill_cache.write_sidecar(meta)
+        skill_cache.store_compact("sess_mc", "userSettings:brainstorming", "compact body")
+        cache_dir = tmp_data_dir / "skills"
+        compact_before = [f for f in cache_dir.iterdir() if f.name.endswith("-compact")]
+        assert compact_before, "compact file should exist before invalidation"
+
+        n = skill_cache.invalidate_for_path(source)
+        assert n == 1
+        compact_after = [f for f in cache_dir.iterdir() if f.name.endswith("-compact")]
+        assert len(compact_after) == 0, "stale compact for mixed-case skill was not purged"
+
     def test_other_skills_not_removed(self, tmp_data_dir):
         """Only entries matching the given path are removed; others are untouched."""
         source_a = "/skills/ralph/SKILL.md"