docs(12-06): complete Plan CLI Commands & Architect Decompose plan

- Add 12-06-SUMMARY.md documenting plan and architect CLI commands
- Update STATE.md position to plan 6/8 and 47 plans completed

.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: 5 of 8 in current phase
+Plan: 6 of 8 in current phase
 Status: In progress
-Last activity: 2026-02-01 — Completed 12-05-PLAN.md
+Last activity: 2026-02-01 — Completed 12-06-PLAN.md
 
-Progress: ██████░░░░ 64%
+Progress: ██████░░░░ 67%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 46
+- Total plans completed: 47
 - Average duration: 3 min
-- Total execution time: 148 min
+- Total execution time: 151 min
 
 **By Phase (v1.0):**
 
@@ -154,6 +154,8 @@ Recent decisions affecting current work:
 - 12-04: createTasksFromDecomposition maps task numbers to IDs for dependency creation
 - 12-05: buildDecomposePrompt takes Plan and Phase (not Initiative) to provide plan-level context
 - 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
 
 ### Pending Todos
 
@@ -174,5 +176,5 @@ None.
 ## Session Continuity
 
 Last session: 2026-02-01
-Stopped at: Completed 12-05-PLAN.md (Decompose Prompts & Spawn Procedure)
+Stopped at: Completed 12-06-PLAN.md (Plan CLI Commands & Architect Decompose)
 Resume file: None