docs: update launcher design for profile and server actions

Document the profile settings added to the launcher design and the new
Start Server detail action. The settings contract now includes a persisted
username and language choice, and the game detail overlay shows Start Server
only for installed games that can host a dedicated server.

The reference mock now includes the matching Profile controls, a server icon,
server-capable sample catalog entries, and the updated detail/settings
artboards so implementation can follow the selected design direction.

Test Plan:
- git diff --cached --check

Refs: design/README.md

design/design_reference/SoftLAN Launcher.html

@@ -35,14 +35,16 @@ const TWEAK_DEFAULTS = /*EDITMODE-BEGIN*/{
   "accent": "#3b82f6",
   "density": "normal",
   "aspect": "square",
-  "bg": "gradient"
+  "bg": "gradient",
+  "username": "d",
+  "language": "en"
 }/*EDITMODE-END*/;
 
 const ACCENTS = ['#3b82f6', '#22d3ee', '#a855f7', '#22c55e', '#f59e0b', '#ef4444'];
 
 function App() {
   const [t, setTweak] = useTweaks(TWEAK_DEFAULTS);
-  const heroGame = GAMES.find(g => g.id === 'ra3'); // installed → modal shows Play + Uninstall
+  const heroGame = GAMES.find(g => g.id === 'cs'); // installed + canHostServer → shows Play + Start Server + Uninstall
 
   return (
     <React.Fragment>
@@ -62,7 +64,7 @@ function App() {
 
         <DCSection id="detail" title="Game detail overlay"
                    subtitle="Opens when you click a card. Full description, metadata, primary action + secondary actions (incl. uninstall).">
-          <DCArtboard id="detail-modal" label="C · Detail overlay (installed game)" width={1340} height={840}>
+          <DCArtboard id="detail-modal" label="C · Detail overlay (installed, can host server)" width={1340} height={840}>
             <Launcher variant="single" tweaks={t} setTweak={setTweak}
                       initialFilter="installed" initialSort="az"
                       initialOpenGame={heroGame}/>
@@ -90,6 +92,13 @@ function App() {
       </DesignCanvas>
 
       <TweaksPanel>
+        <TweakSection label="Profile"/>
+        <TweakText label="Username" value={t.username}
+                   onChange={(v) => setTweak('username', v)}/>
+        <TweakRadio label="Language" value={t.language}
+                    options={[{value: 'en', label: 'English'}, {value: 'de', label: 'Deutsch'}]}
+                    onChange={(v) => setTweak('language', v)}/>
+
         <TweakSection label="Theme"/>
         <TweakColor label="Accent" value={t.accent} options={ACCENTS}
                     onChange={(v) => setTweak('accent', v)}/>