docs(12-07): complete Unit Tests for Decompose Mode & PlanRepository plan

- Add 5 MockAgentManager decompose mode tests
- Add 3 PlanRepository getNextNumber tests
- Update STATE.md with plan 7 completion

.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: 6 of 8 in current phase
+Plan: 7 of 8 in current phase
 Status: In progress
-Last activity: 2026-02-01 — Completed 12-06-PLAN.md
+Last activity: 2026-02-01 — Completed 12-07-PLAN.md
 
-Progress: ██████░░░░ 67%
+Progress: ███████░░░ 75%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 47
+- Total plans completed: 48
 - Average duration: 3 min
-- Total execution time: 151 min
+- Total execution time: 154 min
 
 **By Phase (v1.0):**
 
@@ -176,5 +176,5 @@ None.
 ## Session Continuity
 
 Last session: 2026-02-01
-Stopped at: Completed 12-06-PLAN.md (Plan CLI Commands & Architect Decompose)
+Stopped at: Completed 12-07-PLAN.md (Unit Tests for Decompose Mode & PlanRepository)
 Resume file: None

.planning/phases/12-phase-task-decomposition/12-07-SUMMARY.md

@@ -0,0 +1,112 @@
+---
+phase: 12-phase-task-decomposition
+plan: 07
+subsystem: testing
+tags: [vitest, unit-test, mock-manager, plan-repository, decompose-mode]
+
+# Dependency graph
+requires:
+  - phase: 12-phase-task-decomposition
+    plan: 01
+    provides: TaskBreakdown schema and decompose_complete status
+  - phase: 12-phase-task-decomposition
+    plan: 02
+    provides: PlanRepository.getNextNumber
+  - phase: 12-phase-task-decomposition
+    plan: 03
+    provides: MockAgentManager decompose_complete handling
+provides:
+  - Unit tests for MockAgentManager decompose mode
+  - Unit tests for PlanRepository getNextNumber
+affects: [12-08]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - Decompose mode scenario testing with mock agents
+    - Repository query method testing for getNextNumber
+
+key-files:
+  created: []
+  modified:
+    - src/agent/mock-manager.test.ts
+    - src/db/repositories/drizzle/plan.test.ts
+
+key-decisions: []
+
+# Metrics
+duration: 3min
+completed: 2026-02-01
+---
+
+# Phase 12 Plan 07: Unit Tests for Decompose Mode & PlanRepository Summary
+
+**Added unit tests for MockAgentManager decompose mode and PlanRepository getNextNumber method**
+
+## Performance
+
+- **Duration:** 3 min
+- **Started:** 2026-02-01T11:53:00Z
+- **Completed:** 2026-02-01T11:56:00Z
+- **Tasks:** 2
+- **Files modified:** 2
+
+## Accomplishments
+
+- Added MockAgentManager tests for decompose mode (spawn, complete, questions)
+- Added tests verifying stopped event reasons for decompose_complete
+- Added tests for result message with task count
+- Added PlanRepository getNextNumber tests including edge cases
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Add MockAgentManager decompose mode tests** - `a79b153` (test)
+2. **Task 2: Add PlanRepository getNextNumber tests** - `a615303` (test)
+
+## Files Modified
+
+- `src/agent/mock-manager.test.ts` - Added 'decompose mode' describe block with 5 tests
+- `src/db/repositories/drizzle/plan.test.ts` - Added 'getNextNumber' describe block with 3 tests
+
+## Test Coverage Added
+
+| File | Tests Added | Total Tests |
+|------|-------------|-------------|
+| mock-manager.test.ts | 5 | 44 |
+| plan.test.ts | 3 | 13 |
+
+## Decisions Made
+
+None - plan executed exactly as specified.
+
+## Deviations from Plan
+
+### Adjustments
+
+**1. PlanRepository findByPhaseId tests already existed**
+- Plan specified adding findByPhaseId tests, but these were already implemented in plan.test.ts
+- Only getNextNumber tests were needed
+
+**Total deviations:** 1 (minor scope adjustment)
+**Impact on plan:** Positive - avoided duplication
+
+## Issues Encountered
+
+None
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- All decompose mode tests in place for E2E testing in 12-08
+- PlanRepository methods fully tested
+- Test count: 410 passing
+
+---
+*Phase: 12-phase-task-decomposition*
+*Completed: 2026-02-01*