# Context Manager Task 5 Implementer Report

## Status
- Completed Task 5.
- Required tests pass.
- Full extension test suite passes.

## What you implemented
- Added `src/summaries.ts` with:
  - `buildCompactionSummary()`
  - `buildBranchSummary()`
  - `buildResumePacket()`
- Added `src/persist.ts` with:
  - `SNAPSHOT_ENTRY_TYPE`
  - `RuntimeSnapshot`
  - `serializeSnapshot()`
  - `deserializeLatestSnapshot()`
- Added `src/runtime.ts` with `createContextManagerRuntime()` to:
  - ingest transcript slices via `extractCandidates()` + `mergeCandidates()`
  - observe token pressure via `zoneForTokens()`
  - build packets via `buildContextPacket()`
  - expose compaction, branch, and resume summaries
  - update mode and context window
  - snapshot and restore runtime state
- Added the required tests for summaries, persistence, and runtime.

## What you tested and results
1. Confirmed the new tests initially failed because the new source files did not exist.
   - Command: `cd .pi/agent/extensions/context-manager && npx tsx --test src/summaries.test.ts src/persist.test.ts src/runtime.test.ts`
   - Result: failed with `ERR_MODULE_NOT_FOUND` for `summaries.ts`, `persist.ts`, and `runtime.ts`
2. Ran the required Task 5 tests after implementation.
   - Command: `cd .pi/agent/extensions/context-manager && npx tsx --test src/summaries.test.ts src/persist.test.ts src/runtime.test.ts`
   - Result: 5/5 passing
3. Ran the full extension test suite.
   - Command: `cd .pi/agent/extensions/context-manager && npm test`
   - Result: 29/29 passing

## Files changed
- Created `.pi/agent/extensions/context-manager/src/summaries.ts`
- Created `.pi/agent/extensions/context-manager/src/persist.ts`
- Created `.pi/agent/extensions/context-manager/src/runtime.ts`
- Created `.pi/agent/extensions/context-manager/src/summaries.test.ts`
- Created `.pi/agent/extensions/context-manager/src/persist.test.ts`
- Created `.pi/agent/extensions/context-manager/src/runtime.test.ts`
- Created `.pi/reviews/context-manager-task5-implementer-report.md`

## Self-review findings
- Implementation matches the task-provided API and file list.
- Reused existing `config`, `ledger`, `extract`, and `packet` modules as requested.
- Kept scope to Task 5 only; did not start Task 6.
- Verified the red/green cycle for the new tests.

## Any concerns
- No functional concerns from this task.
- There are unrelated untracked review files already present in `.pi/reviews/`; they were not included in this task’s changes.