feat(mobile): phone Attach button and camera-roll video uploads

A phone-only toolbar Attach button hands the agent a photo or a video with the
keyboard down. It owns its own file input, positioned over the button so iOS
anchors the picker popover to it; the picked paths land on the prompt as unsent
text, so Compose adopts them together with anything already typed and Use
terminal keyboard hands a single-line draft back the other way.

Videos take a second path on the same route: ?kind=video streams the file to
disk under MAX_PASTE_VIDEO_BYTES (1GB, env CODEMAN_MAX_PASTE_VIDEO_BYTES)
instead of buffering it, sniffs the container from the first bytes as they
arrive, drains a mislabeled body unwritten and unlinks on any failure. It draws
on its own 3/min per-(IP, session) rate bucket beside the image path's 30/min:
at 1GB each, 30/min would be 30GB of disk a minute. Without the flag the route
is byte-identical to the image-only version, same 50MB cap and same bucket.

One client classifier, _promptAttachKind (MIME first, then the name's
extension), drives every pick and paste surface: the Attach button, terminal
drop, the tile grid's drop, the Compose and paste-dialog pickers and the
clipboard handlers. A pick that lands while the tile grid owns the terminal
goes to the PTY rather than the parked main-terminal overlay.

docs/wiki/Working-With-Files.md

@@ -155,9 +155,13 @@ expose everyone.
 
 Paste from the clipboard or drag and drop straight onto the terminal. The image is written
 where the agent can read it and the reference is inserted into your prompt. On a phone, the
-image key in the keyboard bar opens the camera or photo library.
+toolbar's Attach button opens the camera or photo library, videos included, and puts the path
+on your prompt, where it behaves like text you typed; the Image button inside the Compose
+editor does the same into the editor. Dropping a video onto the terminal works the same way.
 
 HEIC images from an iPhone are converted to JPEG on the way in.
+Videos (mp4, webm, mov, m4v, ogv) are stored as recorded, up to 1 GB each by default
+(`CODEMAN_MAX_PASTE_VIDEO_BYTES`); they stream to disk rather than through server memory.
 
 ## Generated artifacts