feat(12-03): capability-aware action rendering in StorageBrowser
- Add capabilities, connectionRoot, folderFreshness, lastRefreshedAt, byteAvailability props
- CapabilityButton inline component: aria-disabled, click/Enter/Space/touch suppression
- Gray for unsupported, amber for temporarily_unavailable — no native disabled
- Local defaults preserve all pre-Phase-12 drag/share/move/delete behavior
- Cached-byte marker (clock icon) on size column when byteAvailability='cached'
- No marker for cloud_only
- AppIcon: add info, clock icons
- 50 StorageBrowser tests pass