Release: hard-prune post-compression tool context (#5667)

[nesquena-hermes]

Ships #5667 (@franksong2702) — hard-prune post-compression tool context (#4685).

What

After a compression event, the protected-tail tool-result payloads in the model context are hard-capped to a token budget (applied once, post-compression only), preventing context blowup.

Gate (deep-review re-gate on live head 1350182)

• Byte-identical to PR head. Codex advisor: SAFE TO SHIP, reproduced:
  • Pairing-safe: replaces tool content on a deep copy only, never removes/reorders → every tool_call↔tool_result ID preserved through prune + API sanitization.
  • Model-context-only: assigns s.context_messages; s.messages (visible transcript) retains full tool output (shared-object probe).
  • Post-compression-gated, idempotent, restart-persistent, filtered from display merges.
• Tests: 65 own + 992 regression (compress/context/prune/tool_result/streaming) green.

Closes #5667.

[greptile-apps]

Greptile Summary

This PR adds a post-compression cap for tool-result payloads in model context. The main changes are:

• New hard-prune helpers for compressed context tool outputs.
• Post-compression pruning that updates context_messages without touching the visible transcript.
• Display-merge filters for generated tool-result summaries.
• Tests for pruning, idempotency, API sanitization, and display separation.
• A release changelog entry for the behavior change.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.
• The pruning path is gated to confirmed compression events.
• The visible transcript remains separate from the pruned model context.
• The private summary flag is removed before provider payloads are built.

Important Files Changed

Filename	Overview
api/streaming.py	Adds model-context-only hard pruning after compression and filters generated summaries out of display merges.
tests/test_auto_compression_card.py	Adds focused tests for pruning behavior, idempotency, private flag handling, and transcript preservation.
CHANGELOG.md	Adds the release note for the compressed-context tool-result cap.

_{Reviews (1): Last reviewed commit: "Release: hard-prune post-compression too..." | Re-trigger Greptile}