feat(agent): migrate all remaining tools to YAML specs (21/21 covered)

Adds YAML specs for the 14 tools that were still description-from-docstring:

  filesystem:
    - set_path_for_folder, list_folder, analyze_release, probe_media,
      move_media, manage_subtitles, create_seed_links, learn
  api:
    - find_media_imdb_id, find_torrent, get_torrent_by_index,
      add_torrent_to_qbittorrent, add_torrent_by_index
  language:
    - set_language

Each spec follows the established shape (summary / description /
when_to_use / when_not_to_use / next_steps / parameters with
why_needed + example / returns) and the Python function docstring is
slimmed to a one-line pointer.

Registry now reports: 21 tools, 21 with YAML spec, 0 doc-only.

alfred/agent/tools/specs/create_seed_links.yaml

@@ -0,0 +1,59 @@
+name: create_seed_links
+
+summary: >
+  Recreate the original torrent folder structure with hard-links so
+  qBittorrent can keep seeding after the library move.
+
+description: |
+  Hard-links the library video file back into torrents/<original_folder_name>/
+  and copies all remaining files from the original download folder
+  (subtitles, .nfo, .jpg, .txt, …) so the torrent data is complete on
+  disk. qBittorrent then sees the same content at the location it
+  expects and can keep seeding without rehashing the whole torrent.
+
+when_to_use: |
+  Only when the user has confirmed they want to keep seeding after a
+  move. Call right after manage_subtitles (or after move_media if there
+  are no subs).
+
+when_not_to_use: |
+  - When the user explicitly answered "no" to "keep seeding?".
+  - When the download was not from a torrent (e.g. direct download).
+  - Before the library file is in place — this tool reads it.
+
+next_steps: |
+  - After success: optionally call qBittorrent to update the torrent's
+    save path / force a recheck (not yet covered by a tool).
+  - End the workflow.
+
+parameters:
+  library_file:
+    description: Absolute path to the video file now in the library.
+    why_needed: |
+      The source for the hard-link — same inode means qBittorrent sees
+      identical bytes at the seeding path.
+    example: /tv_shows/Oz.1997.1080p.WEBRip.x265-KONTRAST/Season 03/Oz.S03E01.mkv
+
+  original_download_folder:
+    description: Absolute path to the original download folder.
+    why_needed: |
+      Provides the folder name to recreate under torrents/ and the
+      auxiliary files (subs, nfo, ...) to copy over.
+    example: /downloads/Oz.S03.1080p.WEBRip.x265-KONTRAST
+
+returns:
+  ok:
+    description: Seeding folder rebuilt.
+    fields:
+      status: "'ok'"
+      torrent_subfolder: Absolute path of the recreated folder under torrents/.
+      linked_file: Absolute path of the hard-linked video.
+      copied_files: List of auxiliary files that were copied.
+      copied_count: Number of auxiliary files copied.
+      skipped: List of files skipped (already present, unreadable, ...).
+
+  error:
+    description: Failed to rebuild the seeding folder.
+    fields:
+      error: Short error code.
+      message: Human-readable explanation.