PtcRunner.SubAgent.Compression.SingleUserCoalesced (PtcRunner v0.5.1)

Default compression strategy that coalesces all context into a single USER message.

This strategy transforms multi-turn execution history into a compact, LLM-optimized format. The output structure is:

[
  %{role: :system, content: system_prompt},
  %{role: :user, content: mission + namespaces + history + errors + turns_left}
]

Content Order in USER Message

1. Mission text (always first, never removed)
2. Namespace sections (tools, data/, user/)
3. Expected output (return format from signature)
4. Execution history (tool calls made, println output)
5. Conditional error display (only if last turn failed)
6. Turns indicator ("Turns left: N" or "FINAL TURN - ...")

Error Handling

Uses conditional collapsing based on recovery status:

• If last turn failed: shows most recent error only
• If last turn succeeded: collapses all errors (no error section)