feat(harness): re-anchor after session compaction

[pablontiv]

Re-land of #42 (approved, then closed; head branch deleted, so this is a fresh PR with the same commit). Rebased onto current main (1c218795). Opened as draft for now.

What changed vs the original #42: rebased cleanly — no textual conflict. Composes with #46's autonomous runtime guard (both touch session-level behavior; no double-injection or ordering conflict). The harness logic is byte-identical to the approved commit.

Stacked on #41; cumulative diff until predecessors merge.

Part of #39. Stacked on #41 (review the last commit only).

Summary

• Registers session_compact: sets a one-shot flag so the next context-event reminder carries a post-compaction block (re-check SDD/OpenSpec state on disk, restate scope and acceptance criteria before continuing).
• The flag resets when consumed and at session_start, preventing leakage across sessions.

Changes

File	Change
extensions/gentle-ai.ts	compactionPending flag, session_compact handler, post-compaction block in buildContextReminder(), reset at session_start
tests/gentle-ai.test.ts	One-shot semantics, flag reset through applyHarnessReminder, multi-turn integration scenario

Test plan

• pnpm test green at this commit on current main: 166 pass, 0 fail. Original count on the older base was 65.

Notes

Deliberately minimal v1: no session_before_compact interception and no custom CompactionResult. Those stay open as a possible follow-up if this direction lands well.

Summary by CodeRabbit

• New Features

  • Added a “gentle-harness” reminder that’s injected into outgoing context messages to improve continuity across multi-turn conversations.

• Improvements

  • Updated orchestrator prompt handling to load on demand (no caching) with safe fallback when the prompt file can’t be read.
  • Enhanced reminder logic with compaction-aware, one-time “just compacted” messaging and automatic deduplication so only one reminder is present per turn.

• Tests

  • Expanded unit tests for prompt reload behavior, reminder structure/content, deduplication, and compaction state transitions.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 2287f9e and 9fa4557.

📒 Files selected for processing (2)

• extensions/gentle-ai.ts
• tests/gentle-ai.test.ts

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📝 Walkthrough

Walkthrough

Replaces the cached orchestrator prompt reader with a fresh-read helper (getOrchestratorPromptImpl) that falls back to an empty string on missing files. Adds a compactionPending flag, buildContextReminder, and applyHarnessReminder that inject and deduplicate a harness-reminder message in Pi context events, with the flag set on session_compact and cleared on session_start. New test suite covers all helpers.

Changes

Harness reminder injection and orchestrator prompt refresh

Layer / File(s)	Summary
Orchestrator prompt fresh-read helper extensions/gentle-ai.ts, tests/gentle-ai.test.ts	Replaces orchestratorPromptCache with getOrchestratorPromptImpl(pathOverride?) that reads the markdown file on every call and returns "" on error; exposed via __testing. Tests verify repeated reads reflect disk changes and missing paths return "" without throwing.
Reminder construction and deduplication logic extensions/gentle-ai.ts, tests/gentle-ai.test.ts	Adds reminder content constants, compactionPending flag, buildContextReminder() (conditionally appending a compaction note), and applyHarnessReminder(messages) (filters prior reminders, appends a fresh one). Tests assert correct role/type, required phrases, no mutation of original array, deduplication, mid-array removal, and last-position placement.
Session and context event wiring extensions/gentle-ai.ts	Resets compactionPending at session_start, sets it on session_compact, and transforms outgoing messages via applyHarnessReminder on each context event.
Compaction state and multi-turn reminder tests tests/gentle-ai.test.ts	Tests setCompactionPending/getCompactionPending toggling, a multi-turn scenario confirming exactly one fresh reminder persists across turns, and that applyHarnessReminder resets the pending flag and injects compaction-specific content when pending.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related issues

• feat(harness): strengthen harness persistence using Pi's context and compaction events #39: This PR directly implements the incremental improvements described in that issue — replacing orchestratorPromptCache with getOrchestratorPromptImpl, injecting harness-reminder messages via the context event, and tracking/re-anchoring discipline state across session_compact events using the compactionPending flag.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 12.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat(harness): re-anchor after session compaction' directly describes the main functionality change—reanchoring the harness after session compaction—which is the core objective of the PR.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@extensions/gentle-ai.ts`:
- Around line 1923-1932: The global `compactionPending` variable causes race
conditions across concurrent sessions because multiple sessions can read and
write to it simultaneously without isolation. Replace the single global
`compactionPending` flag with a session-scoped approach: either use a Map keyed
by session identifier (e.g., `compactionPendingBySessionId`) if the `context`
event object contains a stable session/context identifier, or refactor
`buildContextReminder()` and `applyHarnessReminder()` to accept
`compactionPending` as a parameter that is threaded through from session-scoped
state rather than relying on shared global mutable state. Ensure that the
`session_start` reset logic and the `session_compact` event handler are also
updated to work with the session-scoped state instead of the global variable.

In `@tests/gentle-ai.test.ts`:
- Around line 59-64: The test for __testing.getOrchestratorPrompt with a missing
file uses a hardcoded absolute path that is environment-dependent and
unreliable. Instead of using "/nonexistent/path/orchestrator.md", create a
temporary directory dynamically and construct a path to a guaranteed-missing
child file within that temp directory. This ensures the test is deterministic
and works reliably across different environments. Use that
dynamically-constructed missing path when calling
__testing.getOrchestratorPrompt in the test.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

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Configuration used: Repository UI

Review profile: ASSERTIVE

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Run ID: b91eb2f9-4f22-4020-b4ad-551936660f38

📥 Commits

Reviewing files that changed from the base of the PR and between 1c21879 and 3aba486.

📒 Files selected for processing (2)

• extensions/gentle-ai.ts
• tests/gentle-ai.test.ts