Add hot_corners

[rywby-dot]

Like from niri, but more functional

Setup only per output
Support any actions from keybindings, every corner is independent

[outputs.hot_corners]                                                                                                                                
threshold = 4         # activation radius in logical px (default: 4)                                                                                 
top_left = "zoom-to-fit"                                                                                                                             
top_right = "none"                                                                                                                                   
bottom_left = "spawn grim - | wl-copy"                                                                                                               
bottom_right = "exec-launcher"                                                                                                                       
disable_when_fullscreen = true                                
disable_while_dragging  = true

hot-corners.mp4

[malbiruk]

Thanks for this — nice feature, and the config/docs wiring is clean. One must-fix (inline on pointer.rs, it silently disables the whole feature) plus two smaller cleanups, all left inline.

Minor nit not worth a thread: the disable_when_fullscreen early-return doesn't clear hot_corners_armed, so a corner won't re-fire after fullscreen-exit until the cursor leaves and re-enters.

[malbiruk]

Must-fix: held_buttons has no reset path, unlike its sibling suppressed_keys (cleared on VT-switch in keyboard.rs and on PauseSession in udev.rs). Hold a mouse button across a VT switch / suspend and the release is lost → held_buttons stays non-empty → with the default disable_while_dragging = true, every hot corner is dead for the rest of the session. Please clear it at those same two sites.

(Moving this insert/remove above the outputs().is_none() early-return further up also closes the transient output-hotplug variant.)

[malbiruk]

This .cloned() runs on every pointer-motion event for any output with an [[outputs]] block, and OutputConfig.name is a String — so it heap-allocates per event even when no corners are configured. Check bindings.is_empty() on the borrowed ref first, and clone only the fired Action.

[malbiruk]

## renders as an <h2> in the generated docs/config.md, splitting this sentence across the heading and the next paragraph. Use # # prose like the surrounding blocks, then regen: UPDATE_CONFIG_DOCS=1 cargo test docs_config_md_is_up_to_date.