fix(ui): addKeyboardShortcut codegen drops 3-arg calls (modifiers slot missing)

The PERRY_UI_TABLE entry for addKeyboardShortcut declared only 2 args
(Str + Closure), but the runtime FFI takes 3 (key, modifiers, callback)
and every documented example uses the 3-arg form. lower_perry_ui_table_call
hits its arity-mismatch fallback at lower_call.rs:5327 and silently
returns 0.0 — no menu item is installed and no shortcut fires.

Add the missing UiArgKind::F64 modifier slot so codegen, runtime, and
docs all line up. Also update types/perry/ui/index.d.ts to declare the
3-arg form with a doc comment for the modifier bitmap (1=Cmd, 2=Shift,
4=Option, 8=Control), matching the macos/gtk4/windows runtime
implementations.

Verified by recompiling perry-pry: all 7 keyboard shortcuts (Cmd+L,
Cmd+F, Cmd+1, Cmd+2, Cmd+I, Cmd+V, Escape) now appear in the app
menu and their callbacks fire on key press, where previously the
app menu only showed the default Quit item.

Author: proggeramlug

crates/perry-codegen/src/lower_call.rs

@@ -5146,8 +5146,9 @@ const PERRY_UI_TABLE: &[UiSig] = &[
             args: &[], ret: UiReturnKind::F64 },
 
     // ---- Keyboard shortcuts ----
+    // `modifiers` is a bitfield: 1=Cmd, 2=Shift, 4=Option, 8=Control.
     UiSig { method: "addKeyboardShortcut", runtime: "perry_ui_add_keyboard_shortcut",
-            args: &[UiArgKind::Str, UiArgKind::Closure], ret: UiReturnKind::Void },
+            args: &[UiArgKind::Str, UiArgKind::F64, UiArgKind::Closure], ret: UiReturnKind::Void },
 
     // ---- App lifecycle hooks ----
     UiSig { method: "onTerminate", runtime: "perry_ui_app_on_terminate",

types/perry/ui/index.d.ts

@@ -521,7 +521,21 @@ export function pollOpenFile(): string;
 // Keyboard shortcuts
 // ---------------------------------------------------------------------------
 
-export function addKeyboardShortcut(key: string, callback: () => void): void;
+/**
+ * Register a keyboard shortcut that fires `callback` when pressed.
+ *
+ * `modifiers` is a bitfield: `1 = Cmd` (Ctrl on Linux/Windows), `2 = Shift`,
+ * `4 = Option/Alt`, `8 = Control`. Combine with bitwise OR — e.g. Cmd+Shift+S
+ * is `1 | 2` (= `3`). Pass `0` for an unmodified key.
+ *
+ * Must be called before `App({...})` — registrations are buffered and
+ * installed when the menu bar is created.
+ */
+export function addKeyboardShortcut(
+    key: string,
+    modifiers: number,
+    callback: () => void,
+): void;
 
 // ---------------------------------------------------------------------------
 // App lifecycle hooks