feat(blacklist): add Blacklist Manager View

- Create BlacklistManagerView component with list of blocked artists
- Add enable/disable toggle, search filter, and clear all function
- Integrate navigation to blacklist manager from Settings
- Add Content Filtering section in Settings with artist count
- Add i18n translations for English and Spanish
- Wire up view routing in +page.svelte

src/lib/i18n/locales/en.json

@@ -437,6 +437,12 @@
       "fetchArtistImages": "Fetch Qobuz™ Artist Images",
       "fetchArtistImagesDesc": "Show artist photos from Qobuz™ in local library"
     },
+    "contentFiltering": {
+      "title": "Content Filtering",
+      "artistBlacklist": "Artist Blacklist",
+      "manage": "Manage",
+      "disabled": "disabled"
+    },
     "integrations": {
       "title": "Integrations",
       "lastfm": "Last.fm",