LLeMbas's own window, the leaf icon, one name for the app

- The window has no system decoration: a local title bar webview (agent
  state, a native menu with the tray's items, window buttons) above the
  content webview, which stays remote with no IPC. Laid out on resize,
  with a frame to resize by unless maximized.
- Icons from the transparent pixel leaf, not the server's tiled icon.
- productName llembas-desktop: package, .desktop file and the window's
  app id now match (KWin showed a generic icon); the visible name stays
  LLeMbas through a desktop template. Replaces the 0.1.0 package l-le-mbas.
- The bundled CLI is a resource in the app's own directory, not
  /usr/bin/lembas.

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

src-tauri/llembas-desktop.desktop

@@ -0,0 +1,12 @@
+[Desktop Entry]
+Categories={{categories}}
+{{#if comment}}
+Comment={{comment}}
+{{/if}}
+Exec={{exec}}
+StartupWMClass={{exec}}
+Icon={{icon}}
+Name=LLeMbas
+GenericName=LLM workspace
+Terminal=false
+Type=Application