Fix project isolation: Make loadChatHistory respect active project sessions

- Modified loadChatHistory() to check for active project before fetching all sessions
- When active project exists, use project.sessions instead of fetching from API
- Added detailed console logging to debug session filtering
- This prevents ALL sessions from appearing in every project's sidebar

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

public/claude-ide/chat-enhanced.css

@@ -128,6 +128,122 @@
   font-size: 14px;
 }
 
+/* ============================================
+   Archive & Merge Buttons
+   ============================================ */
+
+.chat-history-main {
+  flex: 1;
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  min-width: 0;
+}
+
+.chat-history-archive,
+.chat-history-unarchive {
+  flex-shrink: 0;
+  width: 32px;
+  height: 32px;
+  padding: 0;
+  background: transparent;
+  border: none;
+  border-radius: 6px;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 16px;
+  transition: all 0.2s ease;
+  opacity: 0;
+}
+
+.chat-history-item:hover .chat-history-archive,
+.chat-history-item:hover .chat-history-unarchive {
+  opacity: 0.7;
+}
+
+.chat-history-archive:hover,
+.chat-history-unarchive:hover {
+  opacity: 1 !important;
+  background: #2a2a2a;
+  transform: scale(1.1);
+}
+
+/* Merge selection state */
+.chat-history-item.selected-for-merge {
+  background: #1a3a5a;
+  border-color: #4a9eff;
+}
+
+.chat-history-item.selected-for-merge::before {
+  content: '✓';
+  position: absolute;
+  left: 8px;
+  top: 50%;
+  transform: translateY(-50%);
+  color: #4a9eff;
+  font-weight: bold;
+}
+
+.chat-history-item {
+  position: relative;
+}
+
+/* Merge button */
+#merge-sessions-btn {
+  display: none;
+  position: fixed;
+  bottom: 100px;
+  right: 20px;
+  padding: 12px 20px;
+  background: linear-gradient(135deg, #4a9eff 0%, #a78bfa 100%);
+  color: white;
+  border: none;
+  border-radius: 8px;
+  font-size: 14px;
+  font-weight: 600;
+  cursor: pointer;
+  box-shadow: 0 4px 12px rgba(74, 158, 255, 0.4);
+  z-index: 1000;
+  transition: all 0.2s ease;
+}
+
+#merge-sessions-btn:hover {
+  transform: translateY(-2px);
+  box-shadow: 0 6px 16px rgba(74, 158, 255, 0.5);
+}
+
+/* Archived sessions header button */
+.sidebar-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+}
+
+.sidebar-header-archives {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.btn-show-archives {
+  padding: 6px 12px;
+  background: #2a2a2a;
+  border: 1px solid #444;
+  border-radius: 6px;
+  color: #e0e0e0;
+  font-size: 12px;
+  cursor: pointer;
+  transition: all 0.2s ease;
+}
+
+.btn-show-archives:hover {
+  background: #333;
+  border-color: #4a9eff;
+}
+
 /* ============================================
    Enhanced Message Animations
    ============================================ */
@@ -314,11 +430,12 @@
 }
 
 /* ============================================
-   Enhanced Chat Layout
+   Enhanced Chat Layout - CODENOMAD-INSPIRED
+   Single-screen layout with min-height: 0 pattern
    ============================================ */
 
 .chat-layout {
-  height: calc(100vh - 60px);
+  height: 100%;
   overflow: hidden;
 }
 
@@ -327,10 +444,12 @@
   flex-direction: column;
   height: 100%;
   overflow: hidden;
+  min-height: 0; /* CRITICAL: Enables proper flex growth for nested flex items */
 }
 
 .chat-messages {
   flex: 1;
+  min-height: 0; /* CRITICAL: Allows flex item to shrink below content size */
   overflow-y: auto;
   padding: 20px;
   scroll-behavior: smooth;
@@ -354,11 +473,55 @@
 }
 
 .chat-input-container {
+  flex-shrink: 0; /* CRITICAL: Prevent input container from shrinking */
   border-top: 1px solid #333;
   background: #1a1a1a;
   padding: 16px 20px;
 }
 
+/* Chat Modes Bar - Fixed at bottom above input */
+.chat-modes-bar {
+  flex-shrink: 0; /* CRITICAL: Prevent modes bar from shrinking */
+  display: flex;
+  gap: 4px;
+  padding: 8px 16px;
+  background: #161b22;
+  border-top: 1px solid #333;
+}
+
+.chat-modes-bar .mode-btn {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 12px;
+  background: transparent;
+  border: 1px solid transparent;
+  border-radius: 6px;
+  color: #8b949e;
+  cursor: pointer;
+  transition: all 0.2s ease;
+  font-size: 13px;
+}
+
+.chat-modes-bar .mode-btn:hover {
+  background: #21262d;
+  color: #c9d1d9;
+}
+
+.chat-modes-bar .mode-btn.active {
+  background: #1f6feb;
+  border-color: #58a6ff;
+  color: white;
+}
+
+.mode-icon {
+  font-size: 14px;
+}
+
+.mode-label {
+  font-weight: 500;
+}
+
 /* ============================================
    Message Header Styling
    ============================================ */