feat(agent): summarize and continue at iteration limits

[klaus2000-better]

Summary

• add opt-in agent.summarize_and_continue_on_limit
• force an internal context compaction at each max_turns boundary
• reset the per-window iteration budget and continue the same user turn
• keep hard failures, interrupts, and guardrail halts terminal

Verification

• observed RED before implementation
• 20 targeted config/finalizer/cache tests passed
• 3 targeted conversation-loop tests passed
• git diff --check and Python byte-compilation passed
• hermes doctor: all checks passed

[alt-glitch]

This was generated by AI during triage.

Related to #31418 and spec #16004: this PR uses forced context compaction at the limit, whereas #31418 injects a bounded synthetic continuation turn. These are competing mechanisms; maintainer choice is needed.

[Pdzly]

Sorry, our agent just pushed randomly a change just to our hermes agent, will close it. ( I wanted that it doesnt HARD stop it after the iteration limit is reached.)