refactor(workflows): adopt media.* naming convention

Rename workflow files and their 'name' field with a 'media.' domain
prefix to anticipate future multi-domain expansion (mail.*, calendar.*, ...).

- organize_media -> media.organize_media
- manage_subtitles -> media.manage_subtitles

WorkflowLoader picks them up unchanged (uses data['name']).

alfred/agent/workflows/loader.py

@@ -22,7 +22,7 @@ class WorkflowLoader:
     Usage:
         loader = WorkflowLoader()
         all_workflows = loader.all()
-        workflow = loader.get("organize_media")
+        workflow = loader.get("media.organize_media")
     """
 
     def __init__(self):

alfred/agent/workflows/media.manage_subtitles.yaml

@@ -1,4 +1,4 @@
-name: manage_subtitles
+name: media.manage_subtitles
 description: >
   Place subtitle files alongside a video that has just been organised into the library.
   Detects the release pattern automatically, identifies and classifies all tracks,

alfred/agent/workflows/media.organize_media.yaml

@@ -1,4 +1,4 @@
-name: organize_media
+name: media.organize_media
 description: >
   Organise a downloaded series or movie into the media library.
   Triggered when the user asks to move/organize a specific title.