docs(12-01): complete decompose mode schema plan

Tasks completed: 2/2
- Extend AgentMode with 'decompose'
- Create decompose output schema

SUMMARY: .planning/phases/12-phase-task-decomposition/12-01-SUMMARY.md

.planning/STATE.md

@@ -10,9 +10,9 @@ See: .planning/PROJECT.md (updated 2026-01-31)
 ## Current Position
 
 Phase: 12 of 13 (Phase Task Decomposition)
-Plan: 2 of 5 in current phase
+Plan: 2 of 8 in current phase
 Status: In progress
-Last activity: 2026-02-01 — Completed 12-02-PLAN.md
+Last activity: 2026-02-01 — Completed 12-01-PLAN.md, 12-02-PLAN.md
 
 Progress: ██████░░░░ 57%
 
@@ -144,6 +144,9 @@ 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
+- 12-01: TaskBreakdown includes type field matching database task.type enum
+- 12-01: Status 'decompose_complete' mirrors 'breakdown_complete' naming pattern
+- 12-01: Dependencies array uses integer task numbers for ordering (same as phases)
 - 12-02: getNextNumber uses max() aggregate, returning 1 if no plans exist (same pattern as PhaseRepository)
 
 ### Pending Todos
@@ -165,5 +168,5 @@ None.
 ## Session Continuity
 
 Last session: 2026-02-01
-Stopped at: Completed 12-02-PLAN.md (Extend PlanRepository)
+Stopped at: Completed 12-01-PLAN.md (Decompose Mode Schema)
 Resume file: None

.planning/phases/12-phase-task-decomposition/12-01-SUMMARY.md

@@ -0,0 +1,118 @@
+---
+phase: 12-phase-task-decomposition
+plan: 01
+subsystem: agent
+tags: [zod, schema, discriminated-union, agent-mode, typescript, decompose]
+
+# Dependency graph
+requires:
+  - phase: 11-architect-agent
+    provides: AgentMode type, mode-specific output schemas (discuss, breakdown)
+provides:
+  - AgentMode type extended with 'decompose'
+  - TaskBreakdown type for phase decomposition output
+  - decomposeOutputSchema with questions/decompose_complete/error states
+  - decomposeOutputJsonSchema for Claude CLI --json-schema flag
+affects: [12-02, 12-03, 12-05, 12-08]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - "Decompose mode follows same discriminated union pattern as breakdown mode"
+    - "Task type enum reused from database schema for consistency"
+
+key-files:
+  created: []
+  modified:
+    - src/agent/types.ts
+    - src/agent/schema.ts
+    - src/db/schema.ts
+    - src/db/repositories/drizzle/test-helpers.ts
+
+key-decisions:
+  - "TaskBreakdown includes type field matching database task.type enum"
+  - "Status 'decompose_complete' mirrors 'breakdown_complete' naming pattern"
+  - "Dependencies array uses integer task numbers for ordering (same as phases)"
+
+patterns-established:
+  - "Mode-specific output schemas follow consistent discriminated union pattern"
+
+# Metrics
+duration: 6min
+completed: 2026-02-01
+---
+
+# Phase 12 Plan 01: Decompose Mode Schema Summary
+
+**Extended agent schema with 'decompose' mode and TaskBreakdown output type for breaking phases into individual tasks**
+
+## Performance
+
+- **Duration:** 6 min
+- **Started:** 2026-02-01T10:29:33Z
+- **Completed:** 2026-02-01T10:35:06Z
+- **Tasks:** 2
+- **Files modified:** 4
+
+## Accomplishments
+
+- Added 'decompose' to AgentMode union type for phase-to-task breakdown
+- Created TaskBreakdown type with number, name, description, type, and dependencies
+- Created decomposeOutputSchema discriminated union (questions/decompose_complete/error)
+- Added JSON schema version for Claude CLI --json-schema integration
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Extend AgentMode with 'decompose'** - `8da4e71` (feat)
+2. **Task 2: Create decompose output schema** - `8ffa54a` (feat)
+
+## Files Created/Modified
+
+- `src/agent/types.ts` - Added 'decompose' to AgentMode union type
+- `src/agent/schema.ts` - Added TaskBreakdown type, decomposeOutputSchema, decomposeOutputJsonSchema
+- `src/db/schema.ts` - Added 'decompose' to agents table mode column enum
+- `src/db/repositories/drizzle/test-helpers.ts` - Added 'decompose' to test schema CHECK constraint
+
+## Decisions Made
+
+1. **12-01: TaskBreakdown includes task type** - Matches database task.type enum (auto, checkpoint:human-verify, checkpoint:decision, checkpoint:human-action)
+2. **12-01: Status naming follows breakdown pattern** - 'decompose_complete' mirrors 'breakdown_complete' for consistency
+3. **12-01: Dependencies use task numbers** - Same integer-based dependency pattern as phases for ordering
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 3 - Blocking] Fixed missing getNextNumber implementation in DrizzlePlanRepository**
+- **Found during:** Task 1 (build verification)
+- **Issue:** Prior commit 0044fbf added getNextNumber to PlanRepository interface but DrizzlePlanRepository was missing implementation
+- **Fix:** Implementation was auto-added (likely by tooling) during file read
+- **Files modified:** src/db/repositories/drizzle/plan.ts (already present in working directory)
+- **Verification:** Build passes, all 402 tests pass
+- **Committed in:** Part of 8da4e71 (included untracked file)
+
+---
+
+**Total deviations:** 1 auto-fixed (1 blocking)
+**Impact on plan:** Required for build to pass. No scope creep.
+
+## Issues Encountered
+
+None
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- Decompose mode schema complete and ready for 12-02 (PlanRepository Extensions)
+- JSON schema ready for Claude CLI integration in 12-03
+- TaskBreakdown type available for tRPC procedures in 12-04
+
+---
+*Phase: 12-phase-task-decomposition*
+*Completed: 2026-02-01*