fix(agent-core): trim orphan tool calls from projected context after resume

[meymchen]

Related Issue

Resolve #705
Resolve #701
Resolve #660
Resolve #269
Related #520

Problem

When a session crashes or is killed while a tool call is still in flight, the wire records contain an assistant message with tool_calls but no matching tool result. After kimi resume, ContextMemory.messages projected that malformed tail unchanged, so the next LLM request failed with:

400 an assistant message with 'tool_calls' must be followed by tool messages responding to each 'tool_call_id'. The following tool_call_ids did not have response messages: ...

Manual compaction hit the same error because it also projected the open tool exchange into the compaction prompt.

What changed

• ContextMemory.project() now applies trimTrailingOpenToolExchange() after micro-compaction, so every consumer of the projected history (regular turns, compaction, debug/export views) receives a provider-safe message list.
• Added ContextMemory.cleanupOrphanedToolCalls() which truncates the trailing open exchange from _history, clears pendingToolResultIds / openSteps, and flushes any deferred messages once the exchange is closed.
• Agent.resume() calls cleanupOrphanedToolCalls() immediately after records.replay() and before background.reconcile(), so background notifications and new user input are no longer deferred forever.
• Added the context.cleanup_orphan_tool_calls wire record type so replay remains self-consistent.
• Hardened trimTrailingOpenToolExchange() to leave histories that end in orphan tool messages (no preceding assistant) unchanged instead of returning [].

Checklist

• I have read the CONTRIBUTING document.
• I have linked related issues, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 5165cd4

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@moonshot-ai/agent-core	Patch
@moonshot-ai/kimi-code	Patch

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[meymchen]

Addressed the P1 review feedback from Codex.

When applyCompaction() removes the trailing open tool exchange from _history, it now also clears pendingToolResultIds (only when the new history no longer ends with an open exchange). This prevents later appendUserMessage calls from being deferred forever and flushes any messages that were deferred while the exchange was open.

• Added two regression tests in packages/agent-core/test/agent/context.test.ts.
• Updated the existing packages/agent-core/test/agent/compaction/full.test.ts case whose old expectations contradicted the fix.
• Updated the existing changeset.

All @moonshot-ai/agent-core tests and typecheck pass.