chore(ui): remove the "Start Ralph Loop" button from the start screen

The owner asked for it to go for the next release. The button, its two
style rules and its translation entry are removed; nothing else changes.

The Ralph wizard itself stays in the code, but this button was its only
entry point, so the wizard can no longer be opened from the interface.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/web/public/i18n.js

@@ -1118,7 +1118,6 @@
     'When to use this preset': '此预设的适用场景',
     'Start Loop': '启动循环',
     'Start Ralph Loop': '启动 Ralph 循环',
-    'Start Ralph Loop →': '启动 Ralph 循环 →',
     'Enable Tracker': '启用跟踪器',
     'Ralph / Todo': 'Ralph / 待办',
     'Ralph / Todo Tracker': 'Ralph / 待办跟踪器',

src/web/public/index.html

@@ -590,7 +590,6 @@
             <div class="foreign-sessions" id="foreignSessions" hidden></div>
           </div>
           <p class="welcome-hint">Or click Run to start</p>
-          <button class="welcome-ralph-link" onclick="app.showRalphWizard()">Start Ralph Loop &rarr;</button>
         </div>
       </div>
 

src/web/public/mobile.css

@@ -1847,11 +1847,6 @@ html.mobile-init .file-browser-panel {
     margin-bottom: 0.75rem;
   }
 
-  .welcome-ralph-link {
-    display: block;
-    margin: 0.75rem auto 0;
-  }
-
   .welcome-hint {
     font-size: 0.7rem;
     margin-top: 0.75rem;

src/web/public/styles.css

@@ -5682,21 +5682,6 @@ html[data-skin="og"] .welcome-primary:hover {
   box-shadow: 0 1px 2px rgba(0, 0, 0, 0.15);
 }
 
-.welcome-ralph-link {
-  background: none;
-  border: none;
-  color: var(--text-muted);
-  font-size: 0.75rem;
-  cursor: pointer;
-  padding: 0.25rem 0;
-  margin-top: 0.25rem;
-  transition: color 0.15s ease;
-}
-
-.welcome-ralph-link:hover {
-  color: var(--accent);
-}
-
 /* Short window (a 1470x840 laptop is the common case): the column above now
    fits by construction, but only by taking the space out of the Resume list,
    which collapses to two rows. Buying ~80px back from the vertical rhythm keeps