Add library view and series drill-down (M8)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

README.md

@@ -8,6 +8,9 @@ A terminal UI to search for movies and series with [Radarr](https://radarr.video
   optionally start the automatic search.
 - **Interactive search**: list the releases Radarr/Sonarr find (approved or rejected, with reasons),
   sort and filter them, and grab one. Series: pick a season or a single episode first.
+- **Library**: browse your movies and series, filter by missing / downloaded / monitored, toggle
+  monitoring, trigger searches. Series open into seasons and episodes with per-season and
+  per-episode monitoring, automatic search and release search.
 - **Downloads**: SABnzbd queue and history plus the Radarr/Sonarr queues. Pause/resume, delete,
   retry failed downloads, remove from the arr queue and blocklist.
 - Connection indicators for all three services in the top right; `?` shows every key.
@@ -52,6 +55,8 @@ Keep the file private (`chmod 600`); it holds your API keys.
 | `/` | focus search box |
 | `Enter`, `a` | add selected title |
 | `i` | interactive release search |
+| `m`, `f`, `/`, `t`, `s`, `i`/`Enter`, `r` (library) | movies/series, filter, text filter, monitor, search, releases/episodes, reload |
+| `Enter`, `i`, `s`, `t` (episodes) | expand season / releases, release search, search, monitor |
 | `Enter`/`g`, `s`, `f` (release list) | grab, cycle sort, hide rejected |
 | `p`, `d`, `t`, `b`, `r` (downloads) | pause, delete, retry, blocklist, refresh |
 | `Esc` | back / close dialog |