feat: dashboard-only mode and keystone settings integration

The second display is now optional: [display] enabled = false skips the
headless output, wayvnc, AVNC and the VNC tunnel, so the tablet runs the
dashboard alone. `deck-it env` reports it as EXTEND.

Keystone's new deck-it page (quickshell, desktop/modules/deckit) edits
the config and the autostart line, which needed:

- The user config is merged over the shipped config.toml key by key
  within each table instead of replacing it whole, so the page writes a
  sparse file and an unset key falls back to the default.
- `deck-it defaults` prints the shipped config as JSON for the page's
  placeholders, so keystone never copies the defaults.
- `deck-it status` prints one JSON line (server, display, waiting,
  tablet, extend) for the page's status line and restart check.
- [launch] is now `apps`, a list of desktop ids run with gtk-launch,
  with name and icon read from the .desktop file, so the page can pick
  launchers from the installed apps. The old command tables are gone;
  the client still sends only an id, which must be listed and installed.
  A launcher whose icon the theme lacks shows its name.
- [wifi] address gives the tablet's address in config. The last address
  that worked is kept in ~/.config/deck-it/last-wifi: `stop` deletes the
  runtime serial file, so a restart from the page used to wait forever.
- `stop` also ends a login's `wifi --wait`, matched by its own command
  line only, so repeated restarts do not pile up waiters.

Also fixed: `deck-it env` fell through into the usage text, and the
usage text printed the license header since the header was added.

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

3 files changed, 36 insertions, 10 deletions

diff --git a/tests/test_config.py b/tests/test_config.py
index 879917c..928a8e8 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -35,11 +35,19 @@ class Config(unittest.TestCase):
     def test_rejects_bad_values(self):
         bad = [{"display": {"name": "TAB;rm"}},
                {"display": {"refresh": 0}},
+               {"display": {"enabled": "no"}},
                {"ports": {"command_center": 80}},
-               {"ports": {"command_center": 5900, "display": 5900}}]
+               {"ports": {"command_center": 5900, "display": 5900}},
+               {"wifi": {"address": "x; rm -rf ~"}},
+               {"launch": {"apps": ["ok", "../evil"]}}]
         for cfg in bad:
             self.assertIsNotNone(config.config_error(cfg), cfg)
 
+    def test_user_file_overrides_key_by_key(self):
+        cfg = config.merge({"display": {"enabled": True, "scale": 1}, "launch": {"apps": ["a", "b"]}},
+                           {"display": {"enabled": False}, "launch": {"apps": ["c"]}})
+        self.assertEqual(cfg, {"display": {"enabled": False, "scale": 1}, "launch": {"apps": ["c"]}})
+
     def test_user_config_path_honours_xdg(self):
         self.assertEqual(config.user_config_path().name, "config.toml")
         self.assertEqual(config.user_config_path().parent.name, "deck-it")
diff --git a/tests/test_launcher.py b/tests/test_launcher.py
index 0c16b46..06e5724 100644
--- a/tests/test_launcher.py
+++ b/tests/test_launcher.py
@@ -28,7 +28,7 @@ class Launcher(unittest.TestCase):
     def test_env_prints_keys(self):
         out = subprocess.run(["bash", str(ROOT / "deck-it"), "env"],
                              capture_output=True, text=True, cwd=ROOT).stdout
-        for key in ("MON=", "PORT=", "VNC_PORT="):
+        for key in ("MON=", "PORT=", "VNC_PORT=", "EXTEND="):
             self.assertIn(key, out)
 
 
diff --git a/tests/test_windows.py b/tests/test_windows.py
index e52e23d..e632406 100644
--- a/tests/test_windows.py
+++ b/tests/test_windows.py
@@ -31,10 +31,12 @@ class DesktopIcons(unittest.TestCase):
         from pathlib import Path
         base = Path(tempfile.mkdtemp())
         (base / "com.obsproject.Studio.desktop").write_text(
-            "[Desktop Entry]\nIcon=com.obsproject.Studio\nStartupWMClass=obs\n")
-        mapping = windows._desktop_icons([base])
+            "[Desktop Entry]\nName=OBS Studio\nIcon=com.obsproject.Studio\nStartupWMClass=obs\n"
+            "[Desktop Action x]\nName=Other\n")
+        mapping = windows._desktop_icons(windows._desktop_entries([base]))
         self.assertEqual(mapping["com.obsproject.studio"], ["com.obsproject.Studio", "obs"])
         self.assertEqual(mapping["obs"], ["com.obsproject.Studio", "obs"])
+        self.assertEqual(windows._desktop_entries([base])["com.obsproject.Studio"]["name"], "OBS Studio")
 
 
 class Move(unittest.TestCase):
@@ -86,14 +88,30 @@ class Commands(unittest.TestCase):
             ("hyprctl", "activewindow", "-j"): "{}",
             ("hyprctl", "workspaces", "-j"): '[{"id": 3}]',
         }
-        m = windows.make({
-            "windows": {"workspaces": [1, 2, 3, 4]},
-            "launch": {"obs": {"icon": "obsstudio", "command": "obs"}},
-            "run": lambda cmd: responses[tuple(cmd)],
-        })
+        entries = {"com.obsproject.Studio": {"name": "OBS Studio", "icon": "obs", "wmclass": None}}
+        with mock.patch.object(windows, "_desktop_entries", lambda: entries):
+            m = windows.make({
+                "windows": {"workspaces": [1, 2, 3, 4]},
+                "launch": {"apps": ["com.obsproject.Studio", "not-installed"]},
+                "run": lambda cmd: responses[tuple(cmd)],
+            })
         st = m.state()
         self.assertEqual(st["workspaces"], [1, 2, 3, 4])
-        self.assertEqual(st["launches"], [{"key": "obs", "icon": "obsstudio", "label": "obs"}])
+        self.assertEqual(st["launches"],
+                         [{"key": "com.obsproject.Studio", "icon": "obs", "label": "OBS Studio"}])
+
+    def test_launch_runs_only_listed_installed_apps(self):
+        entries = {"kitty": {"name": "kitty", "icon": "kitty", "wmclass": None},
+                   "other": {"name": "Other", "icon": None, "wmclass": None}}
+        calls = []
+        with mock.patch.object(windows, "_desktop_entries", lambda: entries):
+            m = windows.make({"launch": {"apps": ["kitty", "gone"]}, "run": lambda cmd: "[]"})
+        with mock.patch.object(windows, "_popen", calls.append):
+            m.actions["launch"]({"key": "kitty"})
+            for bad in ("other", "gone", "kitty; rm"):
+                with self.assertRaises(windows.ModuleError):
+                    m.actions["launch"]({"key": bad})
+        self.assertEqual(calls, [["gtk-launch", "kitty"]])
 
 
 if __name__ == "__main__":