optimize key filter

.dev/session-log.md

@@ -0,0 +1,12 @@
+# Session Log
+
+## 2026-05-14 17:20 [saved]
+Goal: Improve song key filter readability.
+Decisions:
+- Use root-key controls with refinement because grouped enharmonic dropdowns were still awkward to change.
+- Keep memory markdown files in `.dev/` because the user requested that location.
+Rejected:
+- Keep all sharp and flat variants as separate primary options.
+- Use a grouped enharmonic dropdown that forces users through reset-like interaction.
+Open:
+- User will review the visual result.