feat: Add platform-specific VLC launch profiles (macOS working; Linux deferred)

- macOS: Uses direct binary path (/Applications/VLC.app/Contents/MacOS/VLC)
  with --no-play-and-exit --play-and-pause flags and AppleScript fullscreen toggle.
  Confirmed working: pause on last frame, stays in window.

- Linux: Uses shell command (vlc --no-play-and-exit --play-and-pause).
  Known issue: not going fullscreen, not pausing on end. Deferred for later
  investigation of flag interpretation vs launcher execution layer.

- Created separate profile constants: VLC_MIRROR_MAC_PROFILE and
  VLC_MIRROR_LINUX_PROFILE in ae_launcher__default_launch_profiles.ts

- Updated TODO__Agents.md with Linux VLC issue for future debugging

Files: ae_launcher__default_launch_profiles.ts, documentation/TODO__Agents.md

documentation/MODULE__AE_Events_PressMgmt_Launcher.md

@@ -335,7 +335,7 @@ tune it later without changing the profile table.
 | `keynote_mac_extend` | `key` | Keynote | `extend` | `1000ms` | Keynote slideshow on the external display if available. Post-script polls `count of documents > 0` before starting — handles slow file load on cold start. |
 | `libreoffice_mac_extend` | `odp` | LibreOffice for macOS | `extend` | `1000ms` | LibreOffice Impress for OpenDocument presentations. |
 | `acrobat_mac_mirror` | `pdf` | Adobe Acrobat for macOS | `mirror` | `1000ms` | PDF handout / deck view uses mirrored display. |
-| `vlc_mirror` | `mp4`, `mkv`, `mp3`, `m4v`, `m4a`, `webm`, `wav`, `aac`, `flac`, `mov`, `mpeg`, `avi`, `flv`, `ogg`, `ogv`, `wmv` | VLC for macOS | `mirror` | `1000ms` | Media playback is mirrored so the room sees the same output as the operator. |
+| `vlc_mirror` | `mp4`, `mkv`, `mp3`, `m4v`, `m4a`, `webm`, `wav`, `aac`, `flac`, `mov`, `mpeg`, `avi`, `flv`, `ogg`, `ogv`, `wmv` | VLC for macOS | `mirror` | `1000ms` | Media playback is mirrored so the room sees the same output as the operator. Uses `--no-play-and-exit` so playback ends on the last frame instead of closing video output. |
 | `powerpoint_win_extend` | `pptxwin`, `pptwin` | PowerPoint for Windows (Parallels) | `extend` | `1500ms` | Windows PowerPoint profile for Parallels-based rooms. Higher base delay to account for Parallels VM startup latency. |
 | `libreoffice_win_extend` | `odpwin` | LibreOffice for Windows | `extend` | `1500ms` | Windows LibreOffice profile for Parallels-based rooms. |
 | `acrobat_win_mirror` | `pdfwin` | Adobe Acrobat for Windows (Parallels) | `mirror` | `1500ms` | Windows PDF profile for mirrored display rooms. |