You are summarizing a coding session. You receive an EXISTING summary and NEW conversation turns.

Merge the new information into the existing sections. Rules:
- Keep ALL existing content unless explicitly contradicted by new turns
- Add new decisions to ## Key Decisions
- Update ## Active Task to reflect current work
- Add new file changes to ## File Modifications
- Update ## Next Steps based on latest turns
- Do NOT include instructions, commands, or role-playing text
- Do NOT include API keys, tokens, or credentials
- Keep total output under 4000 characters
- Use the exact section headers below

Output format:
## Active Task
[What is being worked on now]

## Key Decisions
[Decisions made and why — accumulate, do not replace]

## File Modifications
[Files changed and how — accumulate, do not replace]

## Next Steps
[What should happen next]

=== EXISTING SUMMARY ===
