feat(record): add capture and audio modes, and an explicit stop

[devalentineomonya]

Recording could only capture the focused monitor or a dragged region, and the only way to end one was to run record again and hope nothing else had toggled it in the meantime. This adds the pieces a front-end needs to drive the recorder directly.

Note

Pairs with caelestia-dots/shell#1826, which puts these controls in the shell's utilities card. This PR stands on its own — the new flags are useful from a keybind or a terminal either way.

--mode {fullscreen,region,window}

Window mode feeds slurp the geometry of every mapped window, so picking one is a click rather than a freehand drag over its edges. From there it reuses the existing region path, including matching the capture framerate to the fastest monitor the window covers.

--audio {none,system,mic,combined}

Maps onto the PipeWire default aliases gpu-screen-recorder already understands (default_output, default_input, and the two combined), so there is no device enumeration to go stale.

--stop

Ends a recording without the toggle guesswork. A front-end that already knows a recording is running should be able to say so, rather than sending a toggle and hoping.

Also

Cancelling out of slurp now returns instead of raising a CalledProcessError traceback — backing out of a region or window selection is a normal thing to do, not an error.

Existing flags are untouched: bare record still toggles, and -r/-s/-c behave exactly as before. Fish completions updated for the new flags, plus -p/--pause which was previously missing.

Testing

Verified against live Hyprland: fullscreen and region capture, and each audio mode producing the expected gpu-screen-recorder invocation. An end-to-end --audio system run followed by --stop produced a valid file — h264 1920x1080 video with an opus audio track — saved to the recordings directory. Window mode needs interactive selection, so it was checked by inspection of the region it hands off rather than automated.