Expose key bindings over IPC so a launcher can list them

Asked whether srdwm's bindings show in the AGS launcher. They could not:
srd.bind lives entirely in the Lua engine, and nothing published a binding
anywhere a client could read it. There was no IPC command, no field in any
response, and bound_keys() was used only by main.rs to register grabs.

srd.bind now takes an optional third argument, a description, and the loaded
set is copied into the WindowManager after the initial load and after every
reload. Core neither owns nor interprets them - it has no Lua state and
never dispatches a key - it holds them so the IPC layer, which is handed a
WindowManager and nothing else, can serve them. New `srd keybindings` returns
combo and description pairs, sorted so a UI listing them does not reshuffle
on every refresh.

Every binding in the shipped config now carries a description, so the feature
is useful without the user writing any.

Verified live in a nested instance: 46 bindings published, 0 without a
description, and editing the config file updated the list without a restart
(which also exercised reload-on-write again).

Also verified, for the separate report that windows cannot be moved to
another workspace from the AGS workspace pills: the compositor side works.
`srd dispatch move workspace <id> 2` moved a window from workspace 1 to 2 and
correctly hid it, since workspace 1 was active. Nothing to fix here; the
missing piece is on the shell side.

515 tests pass, clippy clean.

1 files changed, 28 insertions, 28 deletions

diff --git a/config/srd/keybindings.lua b/config/srd/keybindings.lua
index aa3e425..dc315e9 100644
--- a/config/srd/keybindings.lua
+++ b/config/srd/keybindings.lua
@@ -21,25 +21,25 @@ srd.bind("Mod4+3", function()
 end)
 
 - Window management (act on the focused window)
-srd.bind("Mod4+q", function() srd.window.close() end)
-srd.bind("Mod4+m", function() srd.window.minimize() end)
-srd.bind("Mod4+f", function() srd.window.maximize() end)
-srd.bind("Mod4+Shift+space", function() srd.window.toggle_floating() end)
+srd.bind("Mod4+q", function() srd.window.close() end, "Close the focused window")
+srd.bind("Mod4+m", function() srd.window.minimize() end, "Minimize the focused window")
+srd.bind("Mod4+f", function() srd.window.maximize() end, "Maximize or restore the focused window")
+srd.bind("Mod4+Shift+space", function() srd.window.toggle_floating() end, "Float or unfloat the focused window")
 
 - Window navigation (vim-style directional focus)
-srd.bind("Mod4+h", function() srd.window.focus("left") end)
-srd.bind("Mod4+j", function() srd.window.focus("down") end)
-srd.bind("Mod4+k", function() srd.window.focus("up") end)
-srd.bind("Mod4+l", function() srd.window.focus("right") end)
+srd.bind("Mod4+h", function() srd.window.focus("left") end, "Focus the window to the left")
+srd.bind("Mod4+j", function() srd.window.focus("down") end, "Focus the window to the down")
+srd.bind("Mod4+k", function() srd.window.focus("up") end, "Focus the window to the up")
+srd.bind("Mod4+l", function() srd.window.focus("right") end, "Focus the window to the right")
 
 - Move the focused window in a direction, mirroring the focus keys above.
 - `srd.window.move` has existed for a long time and simply had no default
 - binding, so "move window to absolute directions" was unreachable without
 - writing your own config.
-srd.bind("Mod4+Shift+h", function() srd.window.move("left") end)
-srd.bind("Mod4+Shift+j", function() srd.window.move("down") end)
-srd.bind("Mod4+Shift+k", function() srd.window.move("up") end)
-srd.bind("Mod4+Shift+l", function() srd.window.move("right") end)
+srd.bind("Mod4+Shift+h", function() srd.window.move("left") end, "Move the window left")
+srd.bind("Mod4+Shift+j", function() srd.window.move("down") end, "Move the window down")
+srd.bind("Mod4+Shift+k", function() srd.window.move("up") end, "Move the window up")
+srd.bind("Mod4+Shift+l", function() srd.window.move("right") end, "Move the window right")
 
 - Layout switching. srdwm is dynamic-first: "dynamic" is free placement,
 - the default, and tiling is one opt-in layout among several. Mod4+s
@@ -50,30 +50,30 @@ srd.bind("Mod4+s", function()
     else
         srd.layout.set("tiling")
     end
-end)
+end, "Toggle tiling and dynamic layout")
 
 - Lock the session using srdwm's own built-in lock screen. `srd.lock()`
 - talks to the compositor directly rather than shelling out to the control
 - CLI, so it still works when that binary is not on PATH.
-srd.bind("Mod4+Ctrl+l", function() srd.lock() end)
+srd.bind("Mod4+Ctrl+l", function() srd.lock() end, "Lock the session")
 
 - Workspace management
-srd.bind("Mod4+Tab", function() srd.workspace.next() end)
-srd.bind("Mod4+Shift+Tab", function() srd.workspace.prev() end)
+srd.bind("Mod4+Tab", function() srd.workspace.next() end, "Next workspace")
+srd.bind("Mod4+Shift+Tab", function() srd.workspace.prev() end, "Previous workspace")
 
 - Workspace switching with number keys (0 doubles as "workspace 10")
 for i = 0, 9 do
-    srd.bind("Mod4+" .. i, function() srd.workspace.switch(i) end)
-    srd.bind("Mod4+Shift+" .. i, function() srd.workspace.move_window(i) end)
+    srd.bind("Mod4+" .. i, function() srd.workspace.switch(i) end, "Switch to workspace " .. i)
+    srd.bind("Mod4+Shift+" .. i, function() srd.workspace.move_window(i) end, "Move window to workspace " .. i)
 end
 
 - Quick actions
-srd.bind("Mod4+d", function() srd.spawn("rofi -show drun") end)
-srd.bind("Mod4+Return", function() srd.spawn("alacritty") end)
-srd.bind("Mod4+r", function() srd.spawn("rofi -show run") end)
+srd.bind("Mod4+d", function() srd.spawn("rofi -show drun") end, "Application launcher")
+srd.bind("Mod4+Return", function() srd.spawn("alacritty") end, "Open a terminal")
+srd.bind("Mod4+r", function() srd.spawn("rofi -show run") end, "Run a command")
 
 - System
-srd.bind("Mod4+Shift+q", function() srd.quit() end)
+srd.bind("Mod4+Shift+q", function() srd.quit() end, "Quit srdwm")
 
 - Custom function example: toggle window gaps at runtime
 local function toggle_gaps()
@@ -85,13 +85,13 @@ local function toggle_gaps()
         srd.notify("Gaps: On", "info")
     end
 end
-srd.bind("Mod4+g", toggle_gaps)
+srd.bind("Mod4+g", toggle_gaps, "Toggle window gaps")
 
 - Media keys
-srd.bind("XF86AudioRaiseVolume", function() srd.spawn("pactl set-sink-volume @DEFAULT_SINK@ +5%") end)
-srd.bind("XF86AudioLowerVolume", function() srd.spawn("pactl set-sink-volume @DEFAULT_SINK@ -5%") end)
-srd.bind("XF86AudioMute", function() srd.spawn("pactl set-sink-mute @DEFAULT_SINK@ toggle") end)
-srd.bind("XF86MonBrightnessUp", function() srd.spawn("brightnessctl set +5%") end)
-srd.bind("XF86MonBrightnessDown", function() srd.spawn("brightnessctl set 5%-") end)
+srd.bind("XF86AudioRaiseVolume", function() srd.spawn("pactl set-sink-volume @DEFAULT_SINK@ +5%") end, "Volume up")
+srd.bind("XF86AudioLowerVolume", function() srd.spawn("pactl set-sink-volume @DEFAULT_SINK@ -5%") end, "Volume down")
+srd.bind("XF86AudioMute", function() srd.spawn("pactl set-sink-mute @DEFAULT_SINK@ toggle") end, "Mute")
+srd.bind("XF86MonBrightnessUp", function() srd.spawn("brightnessctl set +5%") end, "Brightness up")
+srd.bind("XF86MonBrightnessDown", function() srd.spawn("brightnessctl set 5%-") end, "Brightness down")
 
 print("Key bindings configuration loaded")