feat: compact tool-call write-back for retain noise

[luxus]

Summary

Default retain.compactToolCalls=true so assistant tool calls retain name + primary target only (no full args), matching coding-agents write-back noise discipline.

Linked issue

• Closes feat: compact tool-call write-back for retain noise #561
• Epic epic: adopt coding-agents shortlist (bank strategies, KP seed, git seed, retain compact, eval) #557
• Stack: depends on feat: opt-in gitlog seed and sync readiness #566

Scope

• Compact toolCall projection in messages.ts
• Config retain.compactToolCalls (default true; false for full args)
• Docs + retain/recall tests updated

Verification

• npm run check
• npm run check:coverage (source, tests, critical paths, or ci:coverage)
• npm run typecheck:tsc (source/critical paths or full CI)
• full matrix requested/passed (release PRs/release verification, manual dispatch, platform-sensitive changes, or ci:full)
• package verification requested/passed (release/package changes or ci:package)
• npm run pack:verify (release/package changes)
• npm run smoke:hindsight or configured Hindsight Integration pass (memory-path behavior changes or ci:live-smoke; document unavailable live proof)

Unit tests cover compact default and full-args opt-out. Live smoke not required for pure projection change.

Release impact

• User-visible change

Automatic retain payloads compact tool-call arguments by default.

Risk and rollback

• Risk: less tool argument detail in memory (intentional); set compactToolCalls false to restore.
• Rollback/revert path: revert PR or set compactToolCalls false in config.

Follow-ups

• test: conversation amended-rule consolidation eval tasks #568 eval tasks (top of stack)

Memory invariants

• Retain still stores raw rich content, not summaries.
• Recall Blocks remain ephemeral and are not retained back into Hindsight.
• Project Bank and User Bank isolation is preserved.
• Retain Queue behavior remains queue-first and retry-safe.
• Debug output and sidecars remain opt-in and redacted.
• Import behavior remains deterministic and idempotent when touched.

Guidance sync

• If this changes source-of-truth order, contributor workflow, verification expectations, memory policy, or definition of done, AGENTS.md and CONTRIBUTING.md were updated together.

Agent checklist

• I read and followed AGENTS.md and CONTRIBUTING.md.
• I linked the issue before implementation.
• I kept the diff focused on one vertical slice.
• Final branch contains only focused, reviewable commits.
• I did not bypass hooks or checks.
• I documented skipped checks with reasons.

Notes

User/assistant text is still retained raw; only tool-call argument objects are compacted.

[Copilot]

Pull request overview

This PR introduces a default “compact tool-call” projection to reduce retain noise by storing tool calls as name + primary target instead of full argument payloads, and updates recall formatting to match the compact representation.

Changes:

• Add retain.compactToolCalls (default true) and normalize it into the resolved config.
• Compact assistant tool-call content in both retain projection and recall-query formatting (e.g., [action bash echo hi] and retained { arguments: { target } }).
• Update tests and documentation to reflect the new compact tool-call behavior and the opt-out mode.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/retain.test.ts	Updates expectations for compacted retained tool-call arguments and adds opt-out test coverage.
tests/recall-format.test.ts	Updates recall query formatting expectation from [toolCall …] to [action … target].
extensions/utils/messages.ts	Implements target extraction and compact tool-call formatting/projection.
extensions/types.ts	Adds retain.compactToolCalls to the resolved config type.
extensions/config/config-normalize.ts	Normalizes retain.compactToolCalls from user config with a default.
extensions/config/config-defaults.ts	Enables compact tool-call retention by default (compactToolCalls: true).
docs/memory-behavior.md	Documents the new default compact tool-call behavior and the opt-out setting.

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