Fix: Aggressively kill all bridge processes on startup

[baudbot-agent]

Problem

The slack-bridge frequently fails to start with EADDRINUSE on port 7890 after control-agent restarts. This happens because:

1. Control-agent restarts with a new session ID
2. startup-pi.sh kills the tmux session and tries to kill port holders
3. But a bridge process sometimes survives (detached, zombied, or in a wrong session tree)
4. The orphaned process holds port 7890, causing the new bridge to crash-loop

Solution

Make the cleanup more aggressive:

1. Kill tmux session (stops the restart loop)
2. Kill ALL bridge processes by pattern matching node (broker-)?bridge\.mjs
   • Use SIGTERM first for graceful shutdown
   • Wait 3s, then SIGKILL stragglers
3. Final safety check: kill anything still on port 7890

This ensures no bridge processes survive across control-agent restarts.

Testing

• Manually tested cleanup logic
• Verified pgrep pattern matches both bridge.mjs and broker-bridge.mjs
• Confirmed graceful SIGTERM → SIGKILL fallback works

Impact

• Prevents the common port 7890 conflict that requires manual intervention
• Makes control-agent restarts more reliable
• No change to normal operation (only affects startup cleanup)

[greptile-apps]

Greptile Summary

Improved bridge cleanup robustness by switching from port-based to process pattern matching. The new approach kills all bridge processes (bridge.mjs and broker-bridge.mjs) using SIGTERM with 3s graceful shutdown, then SIGKILL for stragglers, followed by a final port 7890 safety check. This prevents orphaned bridge processes that survive tmux session cleanup from causing EADDRINUSE errors on control-agent restarts.

Key improvements:

• More aggressive cleanup targets all bridge processes by pattern, not just port holders
• Maintains graceful shutdown (SIGTERM → SIGKILL) for clean process termination
• Final safety net still kills anything on port 7890
• Well-documented rationale for the defensive approach

Confidence Score: 5/5

• Safe to merge - defensive cleanup improvement with proper signal handling and fallbacks
• The change is well-designed and addresses a real operational issue. The pgrep pattern correctly matches both bridge types, uses proper SIGTERM→SIGKILL escalation, maintains the port 7890 safety check as fallback, and includes clear documentation. The implementation follows shell best practices with proper error suppression and the pattern won't match test files or other unrelated processes.
• No files require special attention

Important Files Changed

Filename	Overview
pi/skills/control-agent/startup-pi.sh	Changed cleanup strategy from port-based to process pattern matching to prevent orphaned bridge processes

_{Last reviewed commit: 859e043}