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/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "llembas-desktop"
-version = "0.1.0"
+version = "0.2.0"
 description = "LLeMbas Desktop: your LLeMbas server in a window, with the agent on this computer"
 authors = ["Jaroslav Beneš"]
 license = "MIT"
@@ -17,7 +17,7 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 tauri-build = { version = "2", features = [] }
 
 [dependencies]
-tauri = { version = "2", features = ["tray-icon"] }
+tauri = { version = "2", features = ["tray-icon", "unstable"] }
 tauri-plugin-dialog = "2"
 tauri-plugin-opener = "2"
 tauri-plugin-single-instance = "2"