Add queued FFmpeg conversion and finish splitting the window from the host.

Co-authored-by: Cursor <cursoragent@cursor.com>

Backlog.md

@@ -543,16 +543,16 @@ Potential provider:
 
 Possible operations:
 
-- [ ] Video conversion
+- [x] Video conversion
 - [ ] Audio conversion
 - [ ] Codec conversion
 - [ ] Resolution conversion
-- [ ] Extract audio
+- [x] Extract audio
 - [ ] Generate thumbnails
 
 ## Images
 
-- [ ] HEIC -> JPEG
+- [x] HEIC -> JPEG
 - [ ] PNG -> JPEG
 - [ ] Resize
 - [ ] Rotate
@@ -566,6 +566,8 @@ Conversions should support:
 
 and be usable inside File Operation Profiles.
 
+V1: Convert… dialog and an operation-profile Convert toggle. Jobs run on the host through the File Operations Queue. FFmpeg is discovered, not bundled.
+
 ---
 
 # Git Integration
@@ -693,9 +695,9 @@ Discovery: Settings path, then Program Files, then PATH. Missing 7-Zip fails the
 
 ## FFmpeg
 
-Potential:
+`FfmpegConversionExecutor` (`IMediaConversionProvider`)
 
-`MediaConversionProvider`
+Discovery: Settings path, then Program Files, then PATH. Missing FFmpeg fails the queued job with an install hint. FFmpeg is not bundled. V1: H.264 MP4, extract AAC/M4A, HEIC→JPEG. Preview first. Online-only cloud files are not hydrated.
 
 ## Git