docs(12-08): complete TestHarness helpers & decompose E2E tests plan

Tasks completed: 2/2
- Add TestHarness decompose mode helpers
- Add decompose mode E2E tests

Phase 12 complete (8/8 plans).

SUMMARY: .planning/phases/12-phase-task-decomposition/12-08-SUMMARY.md

.planning/ROADMAP.md

@@ -182,12 +182,12 @@ Plans:
 Plans:
 - [x] 12-01: Decompose Mode Schema
 - [x] 12-02: PlanRepository Extensions
-- [ ] 12-03: ClaudeAgentManager Decompose Support
+- [x] 12-03: ClaudeAgentManager Decompose Support
-- [ ] 12-04: Plan & Task tRPC Procedures
+- [x] 12-04: Plan & Task tRPC Procedures
-- [ ] 12-05: Decompose Prompts & Spawn Procedure
+- [x] 12-05: Decompose Prompts & Spawn Procedure
-- [ ] 12-06: CLI Commands
+- [x] 12-06: CLI Commands
-- [ ] 12-07: Unit Tests
+- [x] 12-07: Unit Tests
-- [ ] 12-08: E2E Tests
+- [x] 12-08: E2E Tests
 
 #### Phase 13: Real Claude E2E Tests
 **Goal**: Verify multi-question and architect flows with actual Claude CLI; replace with mocks after verification
@@ -219,7 +219,7 @@ Phases execute in numeric order: 1 → 1.1 → 2 → 3 → 4 → 5 → 6 → 7
 | 9. Extended Scenarios | v1.1 | 2/2 | Complete | 2026-01-31 |
 | 10. Multi-Question Schema | v1.2 | 4/4 | Complete | 2026-01-31 |
 | 11. Architect Agent | v1.2 | 8/8 | Complete | 2026-01-31 |
-| 12. Phase-Task Decomposition | v1.2 | 2/8 | In progress | - |
+| 12. Phase-Task Decomposition | v1.2 | 8/8 | Complete | 2026-02-01 |
 | 13. Real Claude E2E Tests | v1.2 | 0/? | Not started | - |
 
 ---

.planning/STATE.md

@@ -10,18 +10,18 @@ See: .planning/PROJECT.md (updated 2026-01-31)
 ## Current Position
 
 Phase: 12 of 13 (Phase Task Decomposition)
-Plan: 7 of 8 in current phase
+Plan: 8 of 8 in current phase
-Status: In progress
+Status: Phase complete
-Last activity: 2026-02-01 — Completed 12-07-PLAN.md
+Last activity: 2026-02-01 — Completed 12-08-PLAN.md
 
-Progress: ███████░░░ 75%
+Progress: █████████░ 92%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 48
+- Total plans completed: 49
 - Average duration: 3 min
-- Total execution time: 154 min
+- Total execution time: 158 min
 
 **By Phase (v1.0):**
 
@@ -156,6 +156,9 @@ Recent decisions affecting current work:
 - 12-05: spawnArchitectDecompose associates with planId (not initiativeId) matching decompose scope
 - 12-06: Architect decompose added as subcommand under existing architect group (consistent with discuss/breakdown)
 - 12-06: Plan commands follow same pattern as initiative commands for consistency
+- 12-08: planRepository added to harness for plan operations in E2E tests
+- 12-08: Decompose helpers follow same pattern as architect discuss/breakdown helpers
+- 12-08: Agent waiting emits agent:waiting event, not agent:stopped (Q&A flow)
 
 ### Pending Todos
 
@@ -176,5 +179,5 @@ None.
 ## Session Continuity
 
 Last session: 2026-02-01
-Stopped at: Completed 12-07-PLAN.md (Unit Tests for Decompose Mode & PlanRepository)
+Stopped at: Completed 12-08-PLAN.md (TestHarness Helpers & Decompose E2E Tests)
 Resume file: None

.planning/phases/12-phase-task-decomposition/12-08-SUMMARY.md

@@ -0,0 +1,116 @@
+---
+phase: 12-phase-task-decomposition
+plan: 08
+subsystem: test
+tags: [e2e-tests, decompose, test-harness, task-persistence]
+
+# Dependency graph
+requires:
+  - phase: 12-05
+    provides: spawnArchitectDecompose procedure
+  - phase: 12-06
+    provides: Plan CLI commands and architect decompose CLI
+  - phase: 11-08
+    provides: TestHarness architect mode helpers pattern
+provides:
+  - TestHarness with decompose scenario helpers
+  - E2E tests for decompose mode completion and Q&A flow
+  - E2E tests for task persistence from decomposition output
+  - Full workflow test: initiative -> phase -> plan -> decompose -> tasks
+affects: [testing-infrastructure, e2e-coverage]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - "Decompose scenario helpers following architect pattern"
+    - "Plan convenience methods via tRPC caller"
+
+key-files:
+  created:
+    - src/test/e2e/decompose-workflow.test.ts
+  modified:
+    - src/test/harness.ts
+
+key-decisions:
+  - "planRepository added to harness for plan operations"
+  - "Decompose helpers follow same pattern as architect discuss/breakdown helpers"
+  - "Agent waiting emits agent:waiting event, not agent:stopped"
+
+patterns-established:
+  - "TestHarness decompose helpers: setArchitectDecomposeComplete, setArchitectDecomposeQuestions"
+  - "Plan/task convenience methods: createPlan, getTasksForPlan"
+
+# Metrics
+duration: 4min
+completed: 2026-02-01
+---
+
+# Phase 12 Plan 08: TestHarness Helpers & Decompose E2E Tests Summary
+
+**Added TestHarness decompose mode support and comprehensive E2E tests for the complete decomposition workflow**
+
+## Performance
+
+- **Duration:** 4 min
+- **Started:** 2026-02-01T10:53:47Z
+- **Completed:** 2026-02-01T10:57:14Z
+- **Tasks:** 2
+- **Files modified:** 2
+
+## Accomplishments
+
+- Added decompose scenario helpers to TestHarness (setArchitectDecomposeComplete, setArchitectDecomposeQuestions)
+- Added planRepository and plan convenience methods (createPlan, getTasksForPlan)
+- Created comprehensive E2E tests for decompose workflow (7 tests)
+- Validated full workflow: initiative -> phase -> plan -> decompose -> task persistence
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Add TestHarness decompose mode helpers** - `4263c08` (feat)
+2. **Task 2: Add decompose mode E2E tests** - `9b370a2` (test)
+
+## Files Created/Modified
+
+- `src/test/harness.ts` - Added decompose helpers, planRepository, plan convenience methods
+- `src/test/e2e/decompose-workflow.test.ts` - New E2E test file (7 tests)
+
+## Tests Added
+
+- **Spawn decompose complete** - Spawn agent, complete with tasks
+- **Q&A flow** - Pause on questions, resume with answers
+- **Multiple questions** - Handle 3 questions with mixed options
+- **Task persistence** - Create and retrieve tasks from decomposition
+- **All task types** - Verify auto and checkpoint variants
+- **Task dependencies** - Create complex dependency graphs
+- **Full workflow** - Initiative -> phase -> plan -> decompose -> tasks
+
+## Decisions Made
+
+1. **planRepository in harness** - Required for createPlan and task operations
+2. **Decompose helpers pattern** - Follows exact structure of architect discuss/breakdown helpers
+3. **Agent waiting vs stopped** - Questions emit agent:waiting, not agent:stopped
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+
+None
+
+## User Setup Required
+
+None - tests run automatically.
+
+## Next Phase Readiness
+
+- Phase 12 complete - all 8 plans finished
+- Decompose workflow fully tested with E2E coverage
+- Ready for Phase 13 or milestone completion
+
+---
+*Phase: 12-phase-task-decomposition*
+*Completed: 2026-02-01*