feat(settings): drop Token Count + Show Cost header toggles, move Plan Usage Limits to top

The header Token Count and Show Cost ($) display options are superseded by the
Plan Usage Limits chip, so remove both toggles from App Settings → Header
Displays along with their read (populate) and write (save payload) wiring in
settings-ui.js. Relocate the Plan Usage Limits toggle to the top of the section
for easier access.

Header token-chip render logic is left intact (toggles-only change): the chip
keeps its existing default behavior, it's just no longer user-toggleable.

Verified e2e against an isolated instance with Playwright: section now leads
with Plan Usage Limits; Token Count/Show Cost elements are gone; openAppSettings
(populate) and saveAppSettings (payload build) run with no console errors.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/web/public/index.html

@@ -977,6 +977,13 @@
 
               <!-- Header Displays Section -->
               <div class="settings-section-header">Header Displays</div>
+              <div class="settings-item" title="Show Claude plan usage limits (5-hour & weekly) in the header. Applies to newly created sessions.">
+                <span class="settings-item-label">Plan Usage Limits</span>
+                <label class="switch switch-sm">
+                  <input type="checkbox" id="appSettingsShowPlanUsageLimits">
+                  <span class="slider"></span>
+                </label>
+              </div>
               <div class="settings-item" title="Show A-/A+ font size buttons in header">
                 <span class="settings-item-label">Font Controls</span>
                 <label class="switch switch-sm">
@@ -991,20 +998,6 @@
                   <span class="slider"></span>
                 </label>
               </div>
-              <div class="settings-item" title="Show total token count in header">
-                <span class="settings-item-label">Token Count</span>
-                <label class="switch switch-sm">
-                  <input type="checkbox" id="appSettingsShowTokenCount" checked>
-                  <span class="slider"></span>
-                </label>
-              </div>
-              <div class="settings-item" title="Show estimated cost next to token count">
-                <span class="settings-item-label">Show Cost ($)</span>
-                <label class="switch switch-sm">
-                  <input type="checkbox" id="appSettingsShowCost">
-                  <span class="slider"></span>
-                </label>
-              </div>
               <div class="settings-item" title="Show session lifecycle log button in header">
                 <span class="settings-item-label">Lifecycle Log</span>
                 <label class="switch switch-sm">
@@ -1026,13 +1019,6 @@
                   <span class="slider"></span>
                 </label>
               </div>
-              <div class="settings-item" title="Show Claude plan usage limits (5-hour & weekly) in the header. Applies to newly created sessions.">
-                <span class="settings-item-label">Plan Usage Limits</span>
-                <label class="switch switch-sm">
-                  <input type="checkbox" id="appSettingsShowPlanUsageLimits">
-                  <span class="slider"></span>
-                </label>
-              </div>
 
               <!-- Tab Bar Section -->
               <div class="settings-section-header">Tab Bar</div>

src/web/public/settings-ui.js

@@ -305,8 +305,6 @@ Object.assign(CodemanApp.prototype, {
     // Header visibility settings
     document.getElementById('appSettingsShowFontControls').checked = settings.showFontControls ?? defaults.showFontControls ?? false;
     document.getElementById('appSettingsShowSystemStats').checked = settings.showSystemStats ?? defaults.showSystemStats ?? true;
-    document.getElementById('appSettingsShowTokenCount').checked = settings.showTokenCount ?? defaults.showTokenCount ?? true;
-    document.getElementById('appSettingsShowCost').checked = settings.showCost ?? defaults.showCost ?? false;
     document.getElementById('appSettingsShowLifecycleLog').checked = settings.showLifecycleLog ?? defaults.showLifecycleLog ?? true;
     document.getElementById('appSettingsShowResponseViewer').checked = settings.showResponseViewer ?? defaults.showResponseViewer ?? false;
     document.getElementById('appSettingsSkin').value = settings.skin ?? defaults.skin ?? 'daylight-blue';
@@ -1361,8 +1359,6 @@ Object.assign(CodemanApp.prototype, {
       // Header visibility settings
       showFontControls: document.getElementById('appSettingsShowFontControls').checked,
       showSystemStats: document.getElementById('appSettingsShowSystemStats').checked,
-      showTokenCount: document.getElementById('appSettingsShowTokenCount').checked,
-      showCost: document.getElementById('appSettingsShowCost').checked,
       showLifecycleLog: document.getElementById('appSettingsShowLifecycleLog').checked,
       showResponseViewer: document.getElementById('appSettingsShowResponseViewer').checked,
       showMonitor: document.getElementById('appSettingsShowMonitor').checked,