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>

1 files changed, 13 insertions, 6 deletions

diff --git a/README.md b/README.md
index c84bbb2..42f16ae 100644
--- a/README.md
+++ b/README.md
@@ -27,13 +27,14 @@ there is no cloud, account or app-store install.
 
 ```sh
 git clone https://git.danix.xyz/deck-it ~/Programming/GIT/deck-it
-cp ~/Programming/GIT/deck-it/config.toml ~/.config/deck-it/config.toml   # optional
-~/Programming/GIT/deck-it/deck-it
+ln -s ~/Programming/GIT/deck-it/deck-it ~/bin/deck-it
+deck-it
 ```
 
 The launcher creates the headless output, starts wayvnc and the server, tunnels
 them to the tablet, and opens the dashboard and AVNC. `deck-it stop` tears it
-down.
+down. For the dashboard alone, set `enabled = false` under `[display]`: no
+headless output, wayvnc or AVNC.
 
 Over Wi-Fi, pair once and pass the tablet's Wireless debugging address:
 
@@ -42,13 +43,19 @@ deck-it pair
 deck-it wifi 192.168.1.50:41234
 ```
 
+Keystone's settings window has a deck-it page: a Start at login switch (it
+adds `deck-it wifi --wait` to hypr-theme's autostart) and every config key,
+launchers included, with a Restart button to apply a save.
+
 ## Usage
 
 - Tabs: **Dashboard** (draggable/resizable cards), **Windows**, **OBS**. Swipe
   the content sideways to change tab.
-- `deck-it install` prints the `exec-once` line for hypr-theme's autostart.
-- Configuration lives in `config.toml`: workspaces, launcher icons, OBS
-  websocket, llm-cost-dashboard URL, build VM host, hardware overrides.
+- `deck-it install` prints the `exec-once` line for USB autostart.
+- `config.toml` holds the defaults: display, Wi-Fi address, workspaces,
+  launchers (desktop ids), OBS websocket, llm-cost-dashboard URL, build VM
+  host, hardware overrides. `~/.config/deck-it/config.toml` overrides any of
+  them key by key and needs only what differs; keystone writes it.
 - The OBS tab is a stream-deck: scenes, sources, audio sliders, transitions.
   Long-press a source to open its properties dialog in OBS.
 - The Windows tab has workspaces, icon launchers, and a per-window `⋮` menu to