Windows compatibility pass (beta target)

External editor via cmd/start + exe picker; Permissions hidden for
Windows-local (chmod only flips read-only there); Explorer/Recycle Bin
wording; Ctrl vs Cmd shortcut labels; separator-aware path joins +
drive-root detection; drives list in the panel source picker; icon.ico
+ colored tray icon; icacls ACL on connections.json; README Windows
(beta) section with upstream known issues and a smoke-test checklist.
Runtime paths pending first boot on a real Windows machine.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/shared/rpc.ts

@@ -139,6 +139,8 @@ export type AppRPC = {
 			showColumnsMenu: { params: { visible: ColumnKey[] }; response: Result };
 			/** Native About box (name, Build n, commit, engine versions). */
 			showAbout: { params: Record<string, never>; response: Result };
+			/** Windows drive roots for the local panel ("C:\", …); empty elsewhere. */
+			listDrives: { params: Record<string, never>; response: Result<{ drives: string[] }> };
 			// editor windows
 			/** Main window only: open (or focus) a native editor window. */
 			openEditor: { params: EditorOpenContext; response: Result };