Add setup tray entry, wizard progress/log, config add/remove, stale-wine check

- tray: uninstalled launchers now show a "Setup…" entry that spawns
  the setup wizard as a child process.
- setup.rs: download shows a progress bar (bytes / total), and
  umu-run stdout+stderr stream into a scrollable log pane. A 250 ms
  tick subscription pulls updates from the shared state.
- config add-launcher / remove-launcher CLI, with sensible defaults
  for prefix_dir, gameid, and process_pattern derived from name/exe.
- diagnose: flag stale wineserver processes when no launcher is
  running, suggesting `umutray kill`.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -26,9 +26,10 @@ Launch / Kill entries. Users can add or remove launchers in `config edit`.
   prefix / exe / ownership / running state.
 - `service` — installs a `systemd --user` unit so the tray autostarts with
   the graphical session.
-- `setup` — graphical wizard (iced) that downloads an installer URL or
-  accepts a local `.exe`, then runs it via `umu-run` in the launcher's
-  Wine prefix.
+- `setup` — graphical wizard (iced) that downloads an installer URL
+  (with progress bar) or accepts a local `.exe`, then runs it via
+  `umu-run` in the launcher's Wine prefix with a live log pane.
+  Uninstalled launchers expose a **Setup…** entry directly in the tray.
 
 ## Install
 
@@ -65,6 +66,8 @@ umutray service install
 | `umutray config show` / `path`   | Print current config or its file path                   |
 | `umutray config edit`            | Open config in `$EDITOR`                                |
 | `umutray config set …`           | Update globals (`--proton-version`, `--compat-dir`)     |
+| `umutray config add-launcher …`  | Append a new launcher (needs `--exe-path`)              |
+| `umutray config remove-launcher` | Drop a launcher (prefix on disk is left untouched)      |
 | `umutray service install`        | Write + enable a `systemd --user` unit                  |
 | `umutray service uninstall`      | Stop, disable, and remove the unit                      |
 | `umutray service status`         | `systemctl --user status umutray.service`               |