Fix code review issues for phase 2.6 UI polish

Issue 1: Move focusSessionId out of settings to prevent localStorage persistence
- Moved focusSessionId to top-level state property (not in settings)
- Updated all references from state.settings.focusSessionId to state.focusSessionId
- Removed saveSettings() calls from session filter functions

Issue 2: Add active state to wrap toggle button
- Added .active class to wrap-toggle button when wrapText is enabled
- Updated updateSettingsUI() to toggle .active class based on wrapText state

Issue 3: Document auto-scroll ephemeral behavior
- Added comment explaining why auto-scroll is per-session and not persisted
- Clarifies this is intentional design decision

Issue 4: Replace inline styles with CSS class for session filter button
- Added .header-text-btn CSS class with styling
- Removed inline style attribute from sessions-filter-btn

public/index.html

@@ -697,6 +697,13 @@
       font-weight: 600;
     }
 
+    .header-text-btn {
+      font-size: 14px;
+      font-weight: 500;
+      min-width: auto;
+      padding: 8px 12px;
+    }
+
     .popover {
       position: fixed;
       top: 60px;
@@ -864,7 +871,7 @@
   <header>
     <h1>claude-remote</h1>
     <div style="display: flex; align-items: center; gap: 16px;">
-      <button class="settings-btn" id="sessions-filter-btn" onclick="openSessionFilter()" title="Session Filter" style="font-size: 14px; font-weight: 500; min-width: auto; padding: 8px 12px;">
+      <button class="settings-btn header-text-btn" id="sessions-filter-btn" onclick="openSessionFilter()" title="Session Filter">
         <span id="sessions-count-text">0 sessions</span>
       </button>
       <button class="settings-btn" onclick="openStyleModal()" title="Display Settings">⚙️</button>
@@ -968,13 +975,12 @@
       eventSource: null,
       reconnectTimeout: null,
       instructionsModalPromptId: null,
+      focusSessionId: null, // session ID for filtering, null = show all (ephemeral, not persisted)
       settings: {
         columns: 1,           // 1, 2, 3, or 'fit'
         fontSize: 12,         // px value
         terminalHeight: 400,  // px value
         wrapText: true,       // true = pre-wrap, false = pre (horizontal scroll)
-        focusSessionId: null, // session ID for filtering, null = show all
-        autoScroll: true,     // true = auto-scroll to bottom on new output
       },
     };
 
@@ -1042,6 +1048,9 @@
           idle_since: null,
           git_branch: null,
           git_files_json: null,
+          // Auto-scroll state is per-session and ephemeral - not persisted to localStorage.
+          // This is intentional: users may want different auto-scroll settings for different
+          // sessions, and persisting would require tracking state by session ID which is complex.
           autoScroll: true,
         });
         renderSessions();
@@ -1289,14 +1298,13 @@
 
       // Filter sessions if focusSessionId is set
       let sessionsToRender = Array.from(state.sessions.values());
-      if (state.settings.focusSessionId !== null) {
-        const focusSession = state.sessions.get(state.settings.focusSessionId);
+      if (state.focusSessionId !== null) {
+        const focusSession = state.sessions.get(state.focusSessionId);
         if (focusSession) {
           sessionsToRender = [focusSession];
         } else {
           // Filtered session no longer exists, clear filter
-          state.settings.focusSessionId = null;
-          saveSettings();
+          state.focusSessionId = null;
           updateSessionsCountButton();
         }
       }
@@ -1837,7 +1845,13 @@
       document.getElementById('terminal-height-display').textContent = `${state.settings.terminalHeight}px`;
 
       // Update wrap toggle
-      document.getElementById('wrap-toggle').textContent = state.settings.wrapText ? 'On' : 'Off';
+      const $wrapBtn = document.getElementById('wrap-toggle');
+      $wrapBtn.textContent = state.settings.wrapText ? 'On' : 'Off';
+      if (state.settings.wrapText) {
+        $wrapBtn.classList.add('active');
+      } else {
+        $wrapBtn.classList.remove('active');
+      }
     }
 
     window.openStyleModal = () => {
@@ -1893,7 +1907,7 @@
       const $countText = document.getElementById('sessions-count-text');
       const total = state.sessions.size;
 
-      if (state.settings.focusSessionId !== null) {
+      if (state.focusSessionId !== null) {
         $countText.innerHTML = `Viewing 1 of ${total} <span style="margin-left: 4px;">×</span>`;
       } else {
         const label = total === 1 ? 'session' : 'sessions';
@@ -1928,15 +1942,13 @@
     }
 
     window.setSessionFilter = (sessionId) => {
-      state.settings.focusSessionId = Number(sessionId);
-      saveSettings();
+      state.focusSessionId = Number(sessionId);
       closeSessionFilter();
       renderSessions();
     };
 
     window.clearSessionFilter = () => {
-      state.settings.focusSessionId = null;
-      saveSettings();
+      state.focusSessionId = null;
       closeSessionFilter();
       renderSessions();
     };
@@ -1950,7 +1962,7 @@
       }
 
       $list.innerHTML = Array.from(state.sessions.values()).map(s => {
-        const isSelected = state.settings.focusSessionId === s.id;
+        const isSelected = state.focusSessionId === s.id;
         return `
           <div class="session-filter-item ${isSelected ? 'selected' : ''}" onclick="setSessionFilter(${s.id})">
             <div class="session-filter-command">