Project folders for the agent, Local, the menu under its button

- Settings… lists the folders the agent may work in, with the system's
  folder dialog, remove, max mode and terminal, all through
  'lembas remote … --json' (CLI 1.2.0). Turning the agent on with no
  folder opens it; the title bar says 'agent: no folders' instead of green.
- The content webview's User-Agent carries LLeMbasDesktop/<v> (host=…),
  so the server can show this computer's device as Local.
- The title bar menu pops up at the button (popup_menu_at): Wayland gave
  the pointer-less popup the middle of the window.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,21 @@ All notable changes to LLeMbas Desktop. The format follows
 
 ## [Unreleased]
 
+### Added
+
+- **Project folders**: Settings… (in the title bar's and the tray's menu) lists the folders the
+  agent may work in, with *Add folder…* (the system's folder dialog), *Remove*, the most an agent
+  chat may do there, and whether the server may open a terminal. Turning the agent on with no
+  folder chosen opens this page. Changes go through the bundled CLI (`lembas remote`).
+- The server is told it is shown in LLeMbas Desktop and on which computer, so it lists this
+  computer's device as **Local**, first.
+
+### Fixed
+
+- The title bar's menu opens under the button, not in the middle of the window.
+- The agent no longer shows a green light while it may open no folder: the title bar says
+  *agent: no folders*.
+
 ## [0.3.0] — 2026-10-14
 
 ### Added