Move Tree component to @yaakapp-internal/ui package

Decouple Tree from client app's hotkey system by adding
getSelectedItems() to TreeHandle and having callers register
hotkeys externally. Extract shared action callbacks to eliminate
duplication between hotkey and context menu handlers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/yaak-proxy/hotkeys.ts

@@ -0,0 +1,64 @@
+import type {
+  ActionInvocation,
+  ActionMetadata,
+} from "@yaakapp-internal/proxy-lib";
+import { rpc } from "./rpc";
+
+type ActionBinding = {
+  invocation: ActionInvocation;
+  meta: ActionMetadata;
+  keys: { key: string; ctrl: boolean; shift: boolean; alt: boolean; meta: boolean };
+};
+
+/** Parse a hotkey string like "Ctrl+Shift+P" into its parts. */
+function parseHotkey(hotkey: string): ActionBinding["keys"] {
+  const parts = hotkey.split("+").map((p) => p.trim().toLowerCase());
+  return {
+    ctrl: parts.includes("ctrl") || parts.includes("control"),
+    shift: parts.includes("shift"),
+    alt: parts.includes("alt"),
+    meta: parts.includes("meta") || parts.includes("cmd") || parts.includes("command"),
+    key: parts.filter(
+      (p) => !["ctrl", "control", "shift", "alt", "meta", "cmd", "command"].includes(p),
+    )[0] ?? "",
+  };
+}
+
+function matchesEvent(binding: ActionBinding["keys"], e: KeyboardEvent): boolean {
+  return (
+    e.ctrlKey === binding.ctrl &&
+    e.shiftKey === binding.shift &&
+    e.altKey === binding.alt &&
+    e.metaKey === binding.meta &&
+    e.key.toLowerCase() === binding.key
+  );
+}
+
+/** Fetch all actions from Rust and register a global keydown listener. */
+export async function initHotkeys(): Promise<() => void> {
+  const { actions } = await rpc("list_actions", {});
+
+  const bindings: ActionBinding[] = actions
+    .filter(
+      (entry): entry is [ActionInvocation, ActionMetadata & { defaultHotkey: string }] =>
+        entry[1].defaultHotkey != null,
+    )
+    .map(([invocation, meta]) => ({
+      invocation,
+      meta,
+      keys: parseHotkey(meta.defaultHotkey),
+    }));
+
+  function onKeyDown(e: KeyboardEvent) {
+    for (const binding of bindings) {
+      if (matchesEvent(binding.keys, e)) {
+        e.preventDefault();
+        rpc("execute_action", binding.invocation);
+        return;
+      }
+    }
+  }
+
+  window.addEventListener("keydown", onKeyDown);
+  return () => window.removeEventListener("keydown", onKeyDown);
+}