From de5ee8643c5d0484cb5f21b72eaa37b9c513b32e Mon Sep 17 00:00:00 2001
From: arkon <arkon.85@hotmail.com>
Date: Sun, 25 Jan 2026 22:09:45 +0100
Subject: [PATCH] feat: implement DEC mode 2026 synchronized output to reduce
 terminal flicker

- Server wraps SSE terminal batches with DEC 2026 sync markers
- Client extracts and strips markers, writes atomically via RAF batching
- Native terminals (WezTerm, Kitty, etc.) get full sync support
- xterm.js web gets application-layer sync via marker extraction

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 CLAUDE.md                 |   2 +-
 package.json              |   2 +-
 respawn-fixes.md          |  17 +++
 respawn-issues.md         |  13 ++
 respawn-monitor.sh        | 313 ++++++++++++++++++++++++++++++++++++++
 src/web/public/app.js     | 175 +++++++++++++++++++--
 src/web/public/index.html |   9 +-
 src/web/public/styles.css |  19 +++
 8 files changed, 531 insertions(+), 19 deletions(-)
 create mode 100644 respawn-fixes.md
 create mode 100644 respawn-issues.md
 create mode 100755 respawn-monitor.sh

diff --git a/CLAUDE.md b/CLAUDE.md
index aaf23a4e..dca8c62b 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -21,7 +21,7 @@ When user says "COM": 1) Increment version in BOTH `package.json` AND `CLAUDE.md
 
 Claudeman is a Claude Code session manager with a web interface and autonomous Ralph Loop. It spawns Claude CLI processes via PTY, streams output in real-time via SSE, and supports scheduled/timed runs.
 
-**Version**: 0.1367 (must match `package.json`)
+**Version**: 0.1368 (must match `package.json`)
 
 **Tech Stack**: TypeScript (ES2022/NodeNext, strict mode), Node.js, Fastify, Server-Sent Events, node-pty
 
diff --git a/package.json b/package.json
index 6ab2212d..56002fc9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "claudeman",
-  "version": "0.1367",
+  "version": "0.1368",
   "description": "The missing control plane for Claude Code - run 20 autonomous agents with real-time monitoring and session persistence",
   "type": "module",
   "main": "dist/index.js",
diff --git a/respawn-fixes.md b/respawn-fixes.md
new file mode 100644
index 00000000..afdad37c
--- /dev/null
+++ b/respawn-fixes.md
@@ -0,0 +1,17 @@
+# Suggested Fixes for Respawn Controller Issues
+
+**DO NOT EXECUTE** - Waiting for user review
+
+## Fixes
+
+
+### Fix for Issue #1
+**Enable respawn controller**
+
+Via API:
+```bash
+curl -sk -X POST 'https://localhost:3000/api/sessions/5ecdf859-3605-42d8-b0a2-f8f0a1b5ff98/respawn/enable'
+```
+
+Or via web UI: Open session tab -> Respawn panel -> Enable
+
diff --git a/respawn-issues.md b/respawn-issues.md
new file mode 100644
index 00000000..98491c03
--- /dev/null
+++ b/respawn-issues.md
@@ -0,0 +1,13 @@
+# Respawn Controller Issues - w3-reddit-analyse
+
+Monitoring started: Sun Jan 25 09:40:47 PM CET 2026
+Session ID: 5ecdf859-3605-42d8-b0a2-f8f0a1b5ff98
+
+## Issues Detected
+
+
+### Issue #1 [INFO] - 2026-01-25 21:40:48
+**Respawn controller not enabled**
+
+Respawn is currently disabled for this session. State: null
+
diff --git a/respawn-monitor.sh b/respawn-monitor.sh
new file mode 100755
index 00000000..02b63f99
--- /dev/null
+++ b/respawn-monitor.sh
@@ -0,0 +1,313 @@
+#!/bin/bash
+
+# Respawn Controller Monitor for w3-reddit-analyse
+# Monitors for 12 hours, logs issues and suggested fixes
+
+SESSION_ID="5ecdf859-3605-42d8-b0a2-f8f0a1b5ff98"
+SESSION_NAME="w3-reddit-analyse"
+ISSUES_FILE="/home/arkon/default/claudeman/respawn-issues.md"
+FIXES_FILE="/home/arkon/default/claudeman/respawn-fixes.md"
+LOG_FILE="/home/arkon/default/claudeman/respawn-monitor.log"
+API_BASE="https://localhost:3000"
+DURATION_HOURS=12
+POLL_INTERVAL=30  # seconds
+
+# Initialize files
+cat > "$ISSUES_FILE" << 'EOF'
+# Respawn Controller Issues - w3-reddit-analyse
+
+Monitoring started: $(date)
+Session ID: 5ecdf859-3605-42d8-b0a2-f8f0a1b5ff98
+
+## Issues Detected
+
+EOF
+sed -i "s/\$(date)/$(date)/" "$ISSUES_FILE"
+
+cat > "$FIXES_FILE" << 'EOF'
+# Suggested Fixes for Respawn Controller Issues
+
+**DO NOT EXECUTE** - Waiting for user review
+
+## Fixes
+
+EOF
+
+echo "=== Respawn Monitor Started: $(date) ===" > "$LOG_FILE"
+echo "Session: $SESSION_NAME ($SESSION_ID)" >> "$LOG_FILE"
+echo "Duration: $DURATION_HOURS hours" >> "$LOG_FILE"
+echo "Poll interval: ${POLL_INTERVAL}s" >> "$LOG_FILE"
+echo "" >> "$LOG_FILE"
+
+# Track state for anomaly detection
+PREV_STATE=""
+PREV_TOKENS=0
+STATE_STUCK_COUNT=0
+LAST_ACTIVITY_TIME=$(date +%s)
+ISSUE_COUNT=0
+
+log_issue() {
+    local severity="$1"
+    local title="$2"
+    local details="$3"
+    ISSUE_COUNT=$((ISSUE_COUNT + 1))
+
+    echo "" >> "$ISSUES_FILE"
+    echo "### Issue #$ISSUE_COUNT [$severity] - $(date '+%Y-%m-%d %H:%M:%S')" >> "$ISSUES_FILE"
+    echo "**$title**" >> "$ISSUES_FILE"
+    echo "" >> "$ISSUES_FILE"
+    echo "$details" >> "$ISSUES_FILE"
+    echo "" >> "$ISSUES_FILE"
+
+    echo "[$(date '+%H:%M:%S')] ISSUE #$ISSUE_COUNT [$severity]: $title" >> "$LOG_FILE"
+}
+
+log_fix() {
+    local issue_num="$1"
+    local fix_title="$2"
+    local fix_details="$3"
+
+    echo "" >> "$FIXES_FILE"
+    echo "### Fix for Issue #$issue_num" >> "$FIXES_FILE"
+    echo "**$fix_title**" >> "$FIXES_FILE"
+    echo "" >> "$FIXES_FILE"
+    echo "$fix_details" >> "$FIXES_FILE"
+    echo "" >> "$FIXES_FILE"
+}
+
+END_TIME=$(($(date +%s) + DURATION_HOURS * 3600))
+
+while [ $(date +%s) -lt $END_TIME ]; do
+    TIMESTAMP=$(date '+%Y-%m-%d %H:%M:%S')
+
+    # Fetch session status
+    RESPONSE=$(curl -sk "$API_BASE/api/sessions/$SESSION_ID" 2>/dev/null)
+
+    if [ -z "$RESPONSE" ] || [ "$RESPONSE" = "null" ]; then
+        log_issue "CRITICAL" "API request failed or session not found" "Could not fetch session data. Server may be down or session deleted."
+        log_fix "$ISSUE_COUNT" "Check server status" "1. Check if claudeman-web is running: \`systemctl --user status claudeman-web\`
+2. If down, restart: \`systemctl --user restart claudeman-web\`
+3. Check server logs: \`journalctl --user -u claudeman-web -n 50\`"
+        sleep $POLL_INTERVAL
+        continue
+    fi
+
+    # Parse response
+    STATUS=$(echo "$RESPONSE" | jq -r '.status // "unknown"')
+    RESPAWN_ENABLED=$(echo "$RESPONSE" | jq -r '.respawnEnabled // "null"')
+    RESPAWN_STATE=$(echo "$RESPONSE" | jq -r '.respawnState // "null"')
+    INPUT_TOKENS=$(echo "$RESPONSE" | jq -r '.inputTokens // 0')
+    OUTPUT_TOKENS=$(echo "$RESPONSE" | jq -r '.outputTokens // 0')
+    TOTAL_TOKENS=$((INPUT_TOKENS + OUTPUT_TOKENS))
+
+    # Fetch respawn controller details if enabled
+    if [ "$RESPAWN_ENABLED" = "true" ]; then
+        RESPAWN_DETAILS=$(curl -sk "$API_BASE/api/sessions/$SESSION_ID/respawn/status" 2>/dev/null)
+        RESPAWN_STATE=$(echo "$RESPAWN_DETAILS" | jq -r '.state // "unknown"')
+        DETECTION_STATUS=$(echo "$RESPAWN_DETAILS" | jq -r '.detectionStatus // {}')
+        IDLE_CONFIDENCE=$(echo "$DETECTION_STATUS" | jq -r '.idleConfidence // 0')
+        TIME_IN_STATE=$(echo "$RESPAWN_DETAILS" | jq -r '.timeInState // 0')
+        LAST_ERROR=$(echo "$RESPAWN_DETAILS" | jq -r '.lastError // "none"')
+    fi
+
+    echo "[$TIMESTAMP] status=$STATUS respawn=$RESPAWN_ENABLED state=$RESPAWN_STATE tokens=$TOTAL_TOKENS" >> "$LOG_FILE"
+
+    # Check 1: Respawn not enabled when it should be
+    if [ "$RESPAWN_ENABLED" = "null" ] || [ "$RESPAWN_ENABLED" = "false" ]; then
+        if [ -z "$RESPAWN_NOT_ENABLED_LOGGED" ]; then
+            log_issue "INFO" "Respawn controller not enabled" "Respawn is currently disabled for this session. State: $RESPAWN_ENABLED"
+            log_fix "$ISSUE_COUNT" "Enable respawn controller" "Via API:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/enable'
+\`\`\`
+
+Or via web UI: Open session tab -> Respawn panel -> Enable"
+            RESPAWN_NOT_ENABLED_LOGGED=1
+        fi
+    else
+        unset RESPAWN_NOT_ENABLED_LOGGED
+
+        # Check 2: State stuck for too long
+        if [ "$RESPAWN_STATE" = "$PREV_STATE" ] && [ -n "$PREV_STATE" ]; then
+            STATE_STUCK_COUNT=$((STATE_STUCK_COUNT + 1))
+
+            # Stuck in same state for 10+ minutes (20 polls at 30s)
+            if [ $STATE_STUCK_COUNT -ge 20 ]; then
+                STUCK_MINS=$((STATE_STUCK_COUNT * POLL_INTERVAL / 60))
+                log_issue "WARNING" "State stuck: $RESPAWN_STATE for ${STUCK_MINS}+ minutes" "The respawn controller has been in '$RESPAWN_STATE' state for over $STUCK_MINS minutes.
+Time in state: ${TIME_IN_STATE}ms
+Detection status: $DETECTION_STATUS"
+
+                case "$RESPAWN_STATE" in
+                    "watching")
+                        log_fix "$ISSUE_COUNT" "Watching state stuck" "The controller is watching but not detecting idle. Possible causes:
+1. Session is actively working (expected behavior)
+2. Idle detection thresholds too high
+
+Check session activity:
+\`\`\`bash
+curl -sk '$API_BASE/api/sessions/$SESSION_ID' | jq '{status, lastActivityAt}'
+\`\`\`
+
+If truly idle, try adjusting config:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/config' -H 'Content-Type: application/json' -d '{\"idleThresholdMs\": 30000}'
+\`\`\`"
+                        ;;
+                    "confirming_idle")
+                        log_fix "$ISSUE_COUNT" "Confirming idle stuck" "Stuck confirming idle state. The session may be oscillating between idle/working.
+
+Check idle confidence:
+\`\`\`bash
+curl -sk '$API_BASE/api/sessions/$SESSION_ID/respawn/status' | jq '.detectionStatus'
+\`\`\`
+
+Consider increasing confirmation time or check for output patterns that reset detection."
+                        ;;
+                    "ai_checking")
+                        log_fix "$ISSUE_COUNT" "AI check stuck" "AI idle check is taking too long or failing.
+
+Check AI checker status and logs:
+\`\`\`bash
+journalctl --user -u claudeman-web -n 100 | grep -i 'ai.*check\\|idle.*check'
+\`\`\`
+
+The AI checker spawns a separate Claude process. It may be hanging. Consider:
+1. Check for stuck Claude processes: \`ps aux | grep claude\`
+2. Restart the respawn controller:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/stop'
+sleep 2
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/start'
+\`\`\`"
+                        ;;
+                    "sending_"*|"waiting_"*)
+                        log_fix "$ISSUE_COUNT" "Send/wait state stuck" "Stuck in $RESPAWN_STATE - the controller is trying to send a command but may not be receiving expected response.
+
+Check terminal output:
+\`\`\`bash
+curl -sk '$API_BASE/api/sessions/$SESSION_ID/terminal?tail=10000' | tail -100
+\`\`\`
+
+Try restarting respawn:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/stop'
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/start'
+\`\`\`"
+                        ;;
+                    *)
+                        log_fix "$ISSUE_COUNT" "Unknown stuck state" "State '$RESPAWN_STATE' is stuck. Review respawn-controller.ts for this state's expected behavior and transitions."
+                        ;;
+                esac
+                STATE_STUCK_COUNT=0
+            fi
+        else
+            STATE_STUCK_COUNT=0
+            PREV_STATE="$RESPAWN_STATE"
+        fi
+
+        # Check 3: Error in respawn controller
+        if [ "$LAST_ERROR" != "none" ] && [ "$LAST_ERROR" != "null" ] && [ -n "$LAST_ERROR" ]; then
+            log_issue "ERROR" "Respawn controller error" "Error reported: $LAST_ERROR"
+            log_fix "$ISSUE_COUNT" "Resolve respawn error" "Error: $LAST_ERROR
+
+General recovery steps:
+1. Stop respawn: \`curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/stop'\`
+2. Check session health: \`curl -sk '$API_BASE/api/sessions/$SESSION_ID' | jq .\`
+3. Restart respawn: \`curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/start'\`
+
+If error persists, check server logs:
+\`journalctl --user -u claudeman-web -n 200 | grep -i error\`"
+        fi
+
+        # Check 4: Token count not progressing during active work
+        if [ "$STATUS" = "busy" ] && [ "$RESPAWN_STATE" = "watching" ]; then
+            if [ $TOTAL_TOKENS -eq $PREV_TOKENS ] && [ $PREV_TOKENS -gt 0 ]; then
+                TOKENS_STUCK_COUNT=$((TOKENS_STUCK_COUNT + 1))
+                if [ $TOKENS_STUCK_COUNT -ge 10 ]; then  # 5 minutes
+                    log_issue "WARNING" "Tokens not increasing while busy" "Session status is 'busy' but token count hasn't changed in 5+ minutes.
+Current: $TOTAL_TOKENS, Previous: $PREV_TOKENS
+This could indicate a hung Claude process."
+                    log_fix "$ISSUE_COUNT" "Check for hung session" "The session may be hung. Check:
+
+1. Session process status:
+\`\`\`bash
+screen -ls | grep reddit
+\`\`\`
+
+2. Attach to screen and check:
+\`\`\`bash
+screen -r claudeman-w3-reddit-analyse
+# Press Ctrl+A D to detach
+\`\`\`
+
+3. If hung, restart the session via web UI or:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/stop'
+# Then start a new session
+\`\`\`"
+                    TOKENS_STUCK_COUNT=0
+                fi
+            else
+                TOKENS_STUCK_COUNT=0
+            fi
+        fi
+        PREV_TOKENS=$TOTAL_TOKENS
+
+        # Check 5: Rapid state cycling (flapping)
+        if [ "$RESPAWN_STATE" != "$PREV_STATE" ]; then
+            STATE_CHANGES=$((STATE_CHANGES + 1))
+        fi
+
+        # Check every 5 minutes for flapping
+        if [ $((STATE_CHANGES_CHECK_COUNT % 10)) -eq 0 ] && [ $STATE_CHANGES_CHECK_COUNT -gt 0 ]; then
+            if [ $STATE_CHANGES -gt 20 ]; then  # More than 20 state changes in 5 mins
+                log_issue "WARNING" "State flapping detected" "Respawn controller changed states $STATE_CHANGES times in the last 5 minutes. This indicates instability."
+                log_fix "$ISSUE_COUNT" "Reduce state flapping" "The controller is cycling states too rapidly. This usually means:
+1. Idle detection is too sensitive
+2. Session output is oscillating
+
+Adjust detection thresholds:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/respawn/config' -H 'Content-Type: application/json' -d '{
+  \"idleThresholdMs\": 60000,
+  \"completionConfirmMs\": 15000
+}'
+\`\`\`"
+            fi
+            STATE_CHANGES=0
+        fi
+        STATE_CHANGES_CHECK_COUNT=$((STATE_CHANGES_CHECK_COUNT + 1))
+
+        # Check 6: High token usage without respawn cycling
+        if [ $TOTAL_TOKENS -gt 180000 ]; then
+            log_issue "WARNING" "High token usage: $TOTAL_TOKENS" "Token count is very high. Auto-compact or respawn should have triggered by now."
+            log_fix "$ISSUE_COUNT" "Handle high token usage" "Tokens at $TOTAL_TOKENS. Consider:
+
+1. Manual compact:
+\`\`\`bash
+curl -sk -X POST '$API_BASE/api/sessions/$SESSION_ID/input' -H 'Content-Type: application/json' -d '{\"input\": \"/compact\\r\"}'
+\`\`\`
+
+2. Check auto-compact settings:
+\`\`\`bash
+curl -sk '$API_BASE/api/sessions/$SESSION_ID' | jq '{autoCompactEnabled, autoCompactThreshold}'
+\`\`\`"
+        fi
+    fi
+
+    sleep $POLL_INTERVAL
+done
+
+echo "" >> "$ISSUES_FILE"
+echo "---" >> "$ISSUES_FILE"
+echo "Monitoring completed: $(date)" >> "$ISSUES_FILE"
+echo "Total issues detected: $ISSUE_COUNT" >> "$ISSUES_FILE"
+
+echo "" >> "$FIXES_FILE"
+echo "---" >> "$FIXES_FILE"
+echo "Monitoring completed: $(date)" >> "$FIXES_FILE"
+
+echo "" >> "$LOG_FILE"
+echo "=== Monitoring Complete: $(date) ===" >> "$LOG_FILE"
+echo "Total issues: $ISSUE_COUNT" >> "$LOG_FILE"
diff --git a/src/web/public/app.js b/src/web/public/app.js
index 81183152..c77995e1 100644
--- a/src/web/public/app.js
+++ b/src/web/public/app.js
@@ -6,10 +6,63 @@ const DEFAULT_SCROLLBACK = 5000;
 // Wrap terminal writes with these markers to prevent partial-frame flicker.
 // Terminal buffers all output between markers and renders atomically.
 // Supported by: WezTerm, Kitty, Ghostty, iTerm2 3.5+, Windows Terminal, VSCode terminal
-// Unsupported terminals ignore these sequences harmlessly.
+// xterm.js doesn't support DEC 2026 natively, so we implement buffering ourselves.
 const DEC_SYNC_START = '\x1b[?2026h';
 const DEC_SYNC_END = '\x1b[?2026l';
 
+/**
+ * Process data containing DEC 2026 sync markers.
+ * Strips markers and returns segments that should be written atomically.
+ * Each returned segment represents content between SYNC_START and SYNC_END.
+ * Content outside sync blocks is returned as-is.
+ *
+ * @param {string} data - Raw terminal data with potential sync markers
+ * @returns {string[]} - Array of content segments to write (markers stripped)
+ */
+function extractSyncSegments(data) {
+  const segments = [];
+  let remaining = data;
+
+  while (remaining.length > 0) {
+    const startIdx = remaining.indexOf(DEC_SYNC_START);
+
+    if (startIdx === -1) {
+      // No more sync blocks, return rest as-is
+      if (remaining.length > 0) {
+        segments.push(remaining);
+      }
+      break;
+    }
+
+    // Content before sync block (if any)
+    if (startIdx > 0) {
+      segments.push(remaining.slice(0, startIdx));
+    }
+
+    // Find matching end marker
+    const afterStart = remaining.slice(startIdx + DEC_SYNC_START.length);
+    const endIdx = afterStart.indexOf(DEC_SYNC_END);
+
+    if (endIdx === -1) {
+      // No end marker found - sync block continues in next chunk
+      // Include the start marker so it can be handled when more data arrives
+      segments.push(remaining.slice(startIdx));
+      break;
+    }
+
+    // Extract synchronized content (without markers)
+    const syncContent = afterStart.slice(0, endIdx);
+    if (syncContent.length > 0) {
+      segments.push(syncContent);
+    }
+
+    // Continue with content after end marker
+    remaining = afterStart.slice(endIdx + DEC_SYNC_END.length);
+  }
+
+  return segments;
+}
+
 // Notification Manager - Multi-layer browser notification system
 class NotificationManager {
   constructor(app) {
@@ -393,10 +446,11 @@ class ClaudemanApp {
     // Tab alert states: Map<sessionId, 'action' | 'idle'>
     this.tabAlerts = new Map();
 
-    // Terminal write batching
+    // Terminal write batching with DEC 2026 sync support
     this.pendingWrites = '';
     this.writeFrameScheduled = false;
     this._wasAtBottomBeforeWrite = true; // Default to true for sticky scroll
+    this.syncWaitTimeout = null; // Timeout for incomplete sync blocks
 
     // Render debouncing
     this.renderSessionTabsTimeout = null;
@@ -620,23 +674,70 @@ class ClaudemanApp {
     if (!this.writeFrameScheduled) {
       this._wasAtBottomBeforeWrite = this.isTerminalAtBottom();
     }
+
+    // Accumulate raw data (may contain DEC 2026 markers)
     this.pendingWrites += data;
+
     if (!this.writeFrameScheduled) {
       this.writeFrameScheduled = true;
       requestAnimationFrame(() => {
         if (this.pendingWrites && this.terminal) {
-          this.terminal.write(this.pendingWrites);
-          this.pendingWrites = '';
-          // Sticky scroll: if user was at bottom, keep them there after new output
-          if (this._wasAtBottomBeforeWrite) {
-            this.terminal.scrollToBottom();
+          // Check if we have an incomplete sync block (SYNC_START without SYNC_END)
+          const hasStart = this.pendingWrites.includes(DEC_SYNC_START);
+          const hasEnd = this.pendingWrites.includes(DEC_SYNC_END);
+
+          if (hasStart && !hasEnd) {
+            // Incomplete sync block - wait for more data (up to 50ms max)
+            if (!this.syncWaitTimeout) {
+              this.syncWaitTimeout = setTimeout(() => {
+                this.syncWaitTimeout = null;
+                // Force flush after timeout to prevent stuck state
+                this.flushPendingWrites();
+              }, 50);
+            }
+            this.writeFrameScheduled = false;
+            return;
           }
+
+          // Clear any pending sync wait timeout
+          if (this.syncWaitTimeout) {
+            clearTimeout(this.syncWaitTimeout);
+            this.syncWaitTimeout = null;
+          }
+
+          this.flushPendingWrites();
         }
         this.writeFrameScheduled = false;
       });
     }
   }
 
+  /**
+   * Flush pending writes to terminal, processing DEC 2026 sync markers.
+   * Strips markers and writes content atomically within a single frame.
+   */
+  flushPendingWrites() {
+    if (!this.pendingWrites || !this.terminal) return;
+
+    // Extract segments, stripping DEC 2026 markers
+    // This implements synchronized output for xterm.js which doesn't support DEC 2026 natively
+    const segments = extractSyncSegments(this.pendingWrites);
+    this.pendingWrites = '';
+
+    // Write all segments in a single batch (atomic within this frame)
+    // xterm.js internally batches multiple write() calls within same frame
+    for (const segment of segments) {
+      if (segment && !segment.startsWith(DEC_SYNC_START)) {
+        this.terminal.write(segment);
+      }
+    }
+
+    // Sticky scroll: if user was at bottom, keep them there after new output
+    if (this._wasAtBottomBeforeWrite) {
+      this.terminal.scrollToBottom();
+    }
+  }
+
   /**
    * Write large buffer to terminal in chunks to avoid UI jank.
    * Uses requestAnimationFrame to spread work across frames.
@@ -651,24 +752,29 @@ class ClaudemanApp {
         return;
       }
 
-      // For small buffers, write directly with DEC 2026 sync for atomic render
-      if (buffer.length <= chunkSize) {
-        this.terminal.write(DEC_SYNC_START + buffer + DEC_SYNC_END);
+      // Strip any DEC 2026 markers that might be in the buffer
+      // (from historical SSE data that was stored with markers)
+      const cleanBuffer = buffer
+        .replaceAll(DEC_SYNC_START, '')
+        .replaceAll(DEC_SYNC_END, '');
+
+      // For small buffers, write directly
+      if (cleanBuffer.length <= chunkSize) {
+        this.terminal.write(cleanBuffer);
         resolve();
         return;
       }
 
       let offset = 0;
       const writeChunk = () => {
-        if (offset >= buffer.length) {
+        if (offset >= cleanBuffer.length) {
           // Wait one more frame for xterm to finish rendering before resolving
           requestAnimationFrame(() => resolve());
           return;
         }
 
-        const chunk = buffer.slice(offset, offset + chunkSize);
-        // Wrap each chunk with DEC 2026 sync markers for atomic render per frame
-        this.terminal.write(DEC_SYNC_START + chunk + DEC_SYNC_END);
+        const chunk = cleanBuffer.slice(offset, offset + chunkSize);
+        this.terminal.write(chunk);
         offset += chunkSize;
 
         // Schedule next chunk on next frame
@@ -816,8 +922,12 @@ class ClaudemanApp {
           this.terminal.clear();
           this.terminal.reset();
           if (termData.terminalBuffer) {
-            // Wrap with DEC 2026 sync markers for atomic render (prevents flicker)
-            this.terminal.write(DEC_SYNC_START + termData.terminalBuffer + DEC_SYNC_END);
+            // Strip any DEC 2026 markers and write raw content
+            // (markers don't help here - this is a static buffer reload, not live Ink redraws)
+            const cleanBuffer = termData.terminalBuffer
+              .replaceAll(DEC_SYNC_START, '')
+              .replaceAll(DEC_SYNC_END, '');
+            this.terminal.write(cleanBuffer);
           }
 
           // Send resize to ensure proper dimensions
@@ -2957,9 +3067,42 @@ class ClaudemanApp {
 
   closeRunSummary() {
     this.runSummarySessionId = null;
+    this.stopRunSummaryAutoRefresh();
     document.getElementById('runSummaryModal').classList.remove('active');
   }
 
+  async refreshRunSummary() {
+    if (!this.runSummarySessionId) return;
+    await this.loadRunSummary(this.runSummarySessionId);
+  }
+
+  toggleRunSummaryAutoRefresh() {
+    const checkbox = document.getElementById('runSummaryAutoRefresh');
+    if (checkbox.checked) {
+      this.startRunSummaryAutoRefresh();
+    } else {
+      this.stopRunSummaryAutoRefresh();
+    }
+  }
+
+  startRunSummaryAutoRefresh() {
+    if (this.runSummaryAutoRefreshTimer) return;
+    this.runSummaryAutoRefreshTimer = setInterval(() => {
+      if (this.runSummarySessionId) {
+        this.loadRunSummary(this.runSummarySessionId);
+      }
+    }, 5000); // Refresh every 5 seconds
+  }
+
+  stopRunSummaryAutoRefresh() {
+    if (this.runSummaryAutoRefreshTimer) {
+      clearInterval(this.runSummaryAutoRefreshTimer);
+      this.runSummaryAutoRefreshTimer = null;
+    }
+    const checkbox = document.getElementById('runSummaryAutoRefresh');
+    if (checkbox) checkbox.checked = false;
+  }
+
   async loadRunSummary(sessionId) {
     const timeline = document.getElementById('runSummaryTimeline');
     timeline.innerHTML = '<p class="empty-message">Loading summary...</p>';
diff --git a/src/web/public/index.html b/src/web/public/index.html
index 6067bd1f..124d6fd0 100644
--- a/src/web/public/index.html
+++ b/src/web/public/index.html
@@ -514,7 +514,14 @@
         </div>
         <div class="modal-footer">
           <span class="run-summary-session-info" id="runSummarySessionInfo"></span>
-          <button class="btn-toolbar btn-sm" onclick="app.closeRunSummary()">Close</button>
+          <div class="modal-footer-actions">
+            <label class="auto-refresh-label">
+              <input type="checkbox" id="runSummaryAutoRefresh" onchange="app.toggleRunSummaryAutoRefresh()">
+              Auto-refresh
+            </label>
+            <button class="btn-toolbar btn-sm" onclick="app.refreshRunSummary()" title="Refresh summary">&#x21BB; Refresh</button>
+            <button class="btn-toolbar btn-sm" onclick="app.closeRunSummary()">Close</button>
+          </div>
         </div>
       </div>
     </div>
diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index ac136488..342bc987 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -2088,6 +2088,25 @@ body {
   color: var(--text-dim);
 }
 
+.modal-footer-actions {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+}
+
+.auto-refresh-label {
+  display: flex;
+  align-items: center;
+  gap: 0.375rem;
+  font-size: 0.8rem;
+  color: var(--text-dim);
+  cursor: pointer;
+}
+
+.auto-refresh-label input[type="checkbox"] {
+  cursor: pointer;
+}
+
 /* Tab summary icon */
 .tab-summary {
   opacity: 0;