Inbox, library/episode search, subscription sort+tags, episode notes/share, version & commit

- "Nouveautés" sidebar entry (recent episodes across subscriptions); episode
  sort (newest/oldest) in podcast detail.
- Library search (.searchable): filters subscriptions by title and searches
  episodes; results shown in the sidebar.
- Subscription sort (recent/title) and tag filter in the sidebar; per-podcast
  tag editor (TagEditorView), backed by the podcast_tag table.
- Episode notes screen (EpisodeDetailView) with clickable links; "Détails" and
  "Partager" (ShareLink) actions on episode rows.
- Réglages "À propos": app version and git commit (stamped into Info.plist by a
  build phase; ENABLE_USER_SCRIPT_SANDBOXING disabled for the target so git runs).

59 package tests green; iOS + macOS build; inbox, settings (export/version),
player verified in the simulator.

Co-Authored-By: Claude <claude@anthropic.com>