Add multiple fixes

public/index.html

@@ -220,6 +220,13 @@
       align-items: center;
       justify-content: center;
       box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
+      opacity: 0;
+      pointer-events: none;
+    }
+
+    .session-output.scrolled-up .scroll-to-bottom-btn {
+      opacity: 1;
+      pointer-events: auto;
     }
 
     .scroll-to-bottom-btn:hover {
@@ -235,9 +242,10 @@
     .terminal {
       font-family: "SF Mono", Monaco, "Cascadia Code", "Courier New", monospace;
       font-size: var(--font-size);
-      line-height: 1.5;
+      line-height: 1.3;
       white-space: var(--wrap-mode);
-      word-wrap: break-word;
+      word-wrap: normal;
+      overflow-wrap: normal;
       color: #e0e0e0;
     }
 
@@ -1012,7 +1020,7 @@
         columns: 1,           // 1, 2, 3, or 'fit'
         fontSize: 12,         // px value
         terminalHeight: 400,  // px value
-        wrapText: true,       // true = pre-wrap, false = pre (horizontal scroll)
+        wrapText: false,      // true = pre-wrap, false = pre (horizontal scroll)
       },
     };
 
@@ -1043,26 +1051,30 @@
         }
         const sessions = await res.json();
         sessions.forEach(session => {
-          state.sessions.set(session.id, {
+          const existing = state.sessions.get(session.id);
+          const merged = {
             id: session.id,
             cwd: session.cwd,
             command: session.command,
-            output: '',
+            // Preserve any output already received via SSE before fetch completed
-            outputRenderedLength: 0,
+            output: existing?.output ?? '',
-            expanded: false,
+            outputRenderedLength: existing?.outputRenderedLength ?? 0,
-            state: 'ready',
+            // Preserve expansion state
-            prompts: 0,
+            expanded: existing?.expanded ?? false,
-            completions: 0,
+            state: existing?.state ?? 'ready',
-            tools: 0,
+            prompts: existing?.prompts ?? 0,
-            compressions: 0,
+            completions: existing?.completions ?? 0,
-            thinking_seconds: 0,
+            tools: existing?.tools ?? 0,
-            work_seconds: 0,
+            compressions: existing?.compressions ?? 0,
-            mode: 'normal',
+            thinking_seconds: existing?.thinking_seconds ?? 0,
-            model: null,
+            work_seconds: existing?.work_seconds ?? 0,
-            idle_since: null,
+            mode: existing?.mode ?? 'normal',
-            git_branch: null,
+            model: existing?.model ?? null,
-            git_files_json: null,
+            idle_since: existing?.idle_since ?? null,
-          });
+            git_branch: existing?.git_branch ?? null,
+            git_files_json: existing?.git_files_json ?? null,
+          };
+          state.sessions.set(session.id, merged);
         });
         renderSessions();
       } catch (error) {
@@ -1135,13 +1147,36 @@
 
       es.addEventListener('initial_state', (e) => {
         const data = JSON.parse(e.data);
-        const session = state.sessions.get(data.session_id);
+        let session = state.sessions.get(data.session_id);
-        if (session) {
+        if (!session) {
+          // Create a placeholder session so we don't drop the state
+          session = {
+            id: data.session_id,
+            cwd: '',
+            command: 'claude',
+            output: '',
+            outputRenderedLength: 0,
+            expanded: false,
+            state: 'ready',
+            prompts: 0,
+            completions: 0,
+            tools: 0,
+            compressions: 0,
+            thinking_seconds: 0,
+            work_seconds: 0,
+            mode: 'normal',
+            model: null,
+            idle_since: null,
+            git_branch: null,
+            git_files_json: null,
+          };
+          state.sessions.set(data.session_id, session);
+          renderSessions();
+        }
         // Replace output with current terminal state
         session.output = data.html;
         session.outputRenderedLength = 0; // Force re-render
         renderSessionOutput(data.session_id);
-        }
       });
 
       es.addEventListener('output', (e) => {
@@ -1226,6 +1261,10 @@
           // Wait for DOM to update before measuring
           setTimeout(() => {
             handleSessionResize(Number(sessionId));
+            // After mount, ensure we start at bottom and initialize UI state
+            scrollToBottom(Number(sessionId));
+            updateScrollButton(Number(sessionId));
+            initSessionOutputUI(Number(sessionId));
           }, 0);
         }
       }
@@ -1426,6 +1465,12 @@
           </div>
         </div>
       `).join('');
+
+      // Initialize scroll handlers and button visibility
+      sessionsToRender.forEach(s => {
+        initSessionOutputUI(s.id);
+        updateScrollButton(s.id);
+      });
     }
 
     function renderSessionOutput(sessionId) {
@@ -1434,17 +1479,47 @@
 
       const $output = document.getElementById(`output-${sessionId}`);
       if ($output) {
-        // Always full replace since serializeAsHTML() returns full screen state
+        const $outputContainer = document.getElementById(`session-output-${sessionId}`);
+        const shouldStickToBottom =
+          !!($outputContainer && session.expanded && isAtBottom($outputContainer));
+
+        // Only mutate DOM when expanded to reduce work
+        if (session.expanded) {
           $output.innerHTML = session.output;
+        }
         session.outputRenderedLength = session.output.length;
 
-        const $outputContainer = document.getElementById(`session-output-${sessionId}`);
+        if ($outputContainer && session.expanded && shouldStickToBottom) {
-        if ($outputContainer && session.expanded) {
           $outputContainer.scrollTop = $outputContainer.scrollHeight;
         }
+
+        // Update scroll-to-bottom button visibility
+        updateScrollButton(sessionId);
       }
     }
 
+    function isAtBottom(el, threshold = 8) {
+      return el.scrollTop + el.clientHeight >= el.scrollHeight - threshold;
+    }
+
+    function updateScrollButton(sessionId) {
+      const $outputContainer = document.getElementById(`session-output-${sessionId}`);
+      if (!$outputContainer) return;
+      const nearBottom = isAtBottom($outputContainer);
+      if (nearBottom) {
+        $outputContainer.classList.remove('scrolled-up');
+      } else {
+        $outputContainer.classList.add('scrolled-up');
+      }
+    }
+
+    function initSessionOutputUI(sessionId) {
+      const $outputContainer = document.getElementById(`session-output-${sessionId}`);
+      if (!$outputContainer) return;
+      // Attach scroll listener to toggle the button visibility
+      $outputContainer.addEventListener('scroll', () => updateScrollButton(sessionId));
+    }
+
     function updateSessionCard(sessionId) {
       const session = state.sessions.get(sessionId);
       if (!session) return;