Accumulate platform/ctl-crate additions: capture workspace, IPC responses, CLI verbs

Bundles related IPC-surface and CLI additions built up over this
session:
- capture_workspace IPC command + srd capture workspace CLI verb (see
  the wayland-crate commit for the off-screen render this drives).
- Expanded IPC response payloads (monitors, client events, global menu
  info) and their matching CLI plumbing.

Same reasoning as the core-crate sweep commit for why this is coarser
than the repo's usual convention: too entangled to split safely without
a dedicated review pass.

1 files changed, 26 insertions, 0 deletions

diff --git a/crates/platform/src/lib.rs b/crates/platform/src/lib.rs
index 4be9cc4..5de701f 100644
--- a/crates/platform/src/lib.rs
+++ b/crates/platform/src/lib.rs
@@ -8,9 +8,17 @@
 //! pump, macOS's event taps) into the common [`srdwm_core::Event`] queue -
 //! everything downstream of that is platform-independent.
 
+mod appmenu_registrar;
+pub use appmenu_registrar::{AppmenuRegistrarState, RegistrarEvent};
+
 mod ipc;
 pub use ipc::IpcServer;
 
+#[cfg(unix)]
+mod pam_auth;
+#[cfg(unix)]
+pub use pam_auth::authenticate;
+
 use srdwm_core::{Monitor, Rect, Window, WindowId};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -146,4 +154,22 @@ pub trait Platform {
 
     fn grab_keyboard(&mut self) -> Result<()>;
     fn ungrab_keyboard(&mut self) -> Result<()>;
+
+    /// The active XKB layout's own human-readable name (e.g. `"English
+    /// (US)"`) - read once at startup so `WindowManager::keyboard_layout`
+    /// (surfaced over `srd`, for an AGS peer session's keyboard-layout
+    /// badge) has a real value before the first cycle, not an empty string
+    /// until the user cycles once. `Err(Unsupported)` on a backend with no
+    /// real XKB-backed seat to ask (X11, and the honest-stub Windows/macOS
+    /// backends) - same convention `grab_keyboard` already uses for "this
+    /// capability genuinely doesn't exist here" rather than inventing a
+    /// second one.
+    fn keyboard_layout(&mut self) -> Result<String>;
+
+    /// Cycles to the next configured XKB layout (wrapping past the last
+    /// one back to the first) and returns its name. A no-op that returns
+    /// the same name back is correct, not a bug, when only one layout is
+    /// configured - there's nothing to cycle *to*, same as every other
+    /// desktop's layout switcher under the same condition.
+    fn cycle_keyboard_layout(&mut self) -> Result<String>;
 }