docs(12-02): complete PlanRepository extensions plan

Tasks completed: 3/3
- Extend PlanRepository port interface
- Implement methods in DrizzlePlanRepository
- Export types from repositories index (already done)

SUMMARY: .planning/phases/12-phase-task-decomposition/12-02-SUMMARY.md

.planning/ROADMAP.md

@@ -180,8 +180,8 @@ Plans:
 **Plans**: 8
 
 Plans:
-- [ ] 12-01: Decompose Mode Schema
+- [x] 12-01: Decompose Mode Schema
-- [ ] 12-02: PlanRepository Extensions
+- [x] 12-02: PlanRepository Extensions
 - [ ] 12-03: ClaudeAgentManager Decompose Support
 - [ ] 12-04: Plan & Task tRPC Procedures
 - [ ] 12-05: Decompose Prompts & Spawn Procedure
@@ -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 | 0/8 | Planned | - |
+| 12. Phase-Task Decomposition | v1.2 | 2/8 | In progress | - |
 | 13. Real Claude E2E Tests | v1.2 | 0/? | Not started | - |
 
 ---

.planning/STATE.md

@@ -9,12 +9,12 @@ See: .planning/PROJECT.md (updated 2026-01-31)
 
 ## Current Position
 
-Phase: 11 of 13 (Architect Agent)
+Phase: 12 of 13 (Phase Task Decomposition)
-Plan: 8 of 8 in current phase
+Plan: 2 of 5 in current phase
-Status: COMPLETE
+Status: In progress
-Last activity: 2026-01-31 — Completed 11-08-PLAN.md
+Last activity: 2026-02-01 — Completed 12-02-PLAN.md
 
-Progress: █████░░░░░ 55%
+Progress: ██████░░░░ 57%
 
 ## Performance Metrics
 
@@ -144,6 +144,7 @@ Recent decisions affecting current work:
 - 11-08: TestHarness wired with tRPC caller and initiative/phase repositories
 - 11-08: Architect scenario helpers via MockAgentManager (context_complete, breakdown_complete)
 - 11-08: E2E tests cover full discuss -> breakdown -> phase persistence workflow
+- 12-02: getNextNumber uses max() aggregate, returning 1 if no plans exist (same pattern as PhaseRepository)
 
 ### Pending Todos
 
@@ -163,6 +164,6 @@ None.
 
 ## Session Continuity
 
-Last session: 2026-01-31
+Last session: 2026-02-01
-Stopped at: Completed Phase 11 (Architect Agent) — all 8 plans finished
+Stopped at: Completed 12-02-PLAN.md (Extend PlanRepository)
 Resume file: None

.planning/phases/12-phase-task-decomposition/12-02-SUMMARY.md

@@ -0,0 +1,105 @@
+---
+phase: 12-phase-task-decomposition
+plan: 02
+subsystem: database
+tags: [drizzle, repository, hexagonal, ports-adapters]
+
+# Dependency graph
+requires:
+  - phase: 02-data-layer
+    provides: Repository pattern, Drizzle ORM setup
+  - phase: 11-architect-agent
+    provides: Pattern reference for repository extensions
+provides:
+  - PlanRepository.findByPhaseId method (already existed)
+  - PlanRepository.getNextNumber method
+affects: [12-phase-task-decomposition, decompose-agent]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - Aggregate queries with drizzle max() for sequence generation
+
+key-files:
+  created: []
+  modified:
+    - src/db/repositories/plan-repository.ts
+    - src/db/repositories/drizzle/plan.ts
+
+key-decisions:
+  - "getNextNumber uses max() aggregate, returning 1 if no plans exist (same pattern as PhaseRepository)"
+  - "findByPhaseId already existed - only getNextNumber was new"
+
+# Metrics
+duration: 2min
+completed: 2026-02-01
+---
+
+# Phase 12 Plan 02: Extend PlanRepository Summary
+
+**Extended PlanRepository with getNextNumber method for plan sequence generation in decomposition workflow**
+
+## Performance
+
+- **Duration:** 2 min
+- **Started:** 2026-02-01T10:30:00Z
+- **Completed:** 2026-02-01T10:32:19Z
+- **Tasks:** 3
+- **Files modified:** 2
+
+## Accomplishments
+
+- Added `getNextNumber` method to PlanRepository interface for getting next available plan number
+- Implemented `getNextNumber` in DrizzlePlanRepository using max() aggregate query
+- Verified all existing types already properly exported from repositories index
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Extend PlanRepository port interface** - `0044fbf` (feat)
+2. **Task 2: Implement methods in DrizzlePlanRepository** - `3187e2a` (feat)
+3. **Task 3: Export types from repositories index** - No commit needed (types already exported)
+
+## Files Created/Modified
+
+- `src/db/repositories/plan-repository.ts` - Added getNextNumber method signature
+- `src/db/repositories/drizzle/plan.ts` - Implemented getNextNumber with max() query
+
+## Decisions Made
+
+1. **getNextNumber uses max() aggregate** - Returns MAX(number) + 1, or 1 if no plans exist for phase (same pattern as DrizzlePhaseRepository)
+2. **findByPhaseId already existed** - Plan mentioned adding it but it was already in the interface and implemented
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Scope Adjustment] findByPhaseId already existed**
+- **Found during:** Task 1 (interface extension)
+- **Issue:** Plan specified adding findByPhaseId but it already existed in both interface and adapter
+- **Resolution:** Only added getNextNumber as that was the only missing method
+- **Impact:** None - plan outcome achieved
+
+**Total deviations:** 1 (scope adjustment - findByPhaseId already present)
+**Impact on plan:** No negative impact - result matches plan intent
+
+## Issues Encountered
+
+None - all methods implemented successfully, all 402 tests pass.
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- PlanRepository now has all methods needed for decompose agent workflow
+- findByPhaseId: Get all plans for a phase
+- getNextNumber: Get next available plan number for sequence generation
+- Ready for 12-03-PLAN.md (tRPC procedures for task decomposition)
+
+---
+*Phase: 12-phase-task-decomposition*
+*Completed: 2026-02-01*