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, 12 insertions, 0 deletions

diff --git a/crates/core/src/manager/mod.rs b/crates/core/src/manager/mod.rs
index 2ca2bf9..a225220 100644
--- a/crates/core/src/manager/mod.rs
+++ b/crates/core/src/manager/mod.rs
@@ -439,6 +439,17 @@ pub struct WindowManager {
     /// above it. A top bar's own reservation is always honoured either
     /// way. Default `true` - see `input::layers::maximize_geometry_for`.
     pub maximize_covers_dock: bool,
+    /// Every key binding as `(combo, description)`, published by the main
+    /// loop after the config loads and after every reload.
+    ///
+    /// Core neither owns nor interprets these - it has no Lua state and
+    /// never dispatches a key itself. It holds them so the IPC layer, which
+    /// is handed a `WindowManager` and nothing else, can serve them to a
+    /// panel or launcher that wants to show the user what their keys do.
+    /// Asked for as whether "our bindings show in ags's launcher": they
+    /// could not, because nothing published them anywhere a client could
+    /// read.
+    pub keybindings: Vec<(String, String)>,
     /// Set by `request_refresh`, drained by the main loop. Same
     /// cross-boundary queued-request shape as `lock_requested`.
     refresh_requested: bool,
@@ -628,6 +639,7 @@ impl WindowManager {
             auto_raise: false,
             theme: ThemeConfig::default(),
             lock: LockConfig::default(),
+            keybindings: Vec::new(),
             maximize_covers_dock: true,
             refresh_requested: false,
             live_settings: std::collections::BTreeMap::new(),