docs(06): create phase plan

Phase 06: n8n API Access
- 1 plan in 1 wave
- 0 parallel (sequential due to human checkpoint)
- Ready for execution

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -19,6 +19,11 @@ Enable faster development iteration via n8n API access, improve UX with inline k
 
 **Requirements:** API-01, API-02, API-03, API-04
 
+**Plans:** 1 plan
+
+Plans:
+- [ ] 06-01-PLAN.md — Enable API access (create key, verify CRUD, execution history)
+
 **Success Criteria:**
 1. n8n API key exists and Claude Code can authenticate against the n8n API
 2. Claude Code can retrieve the current workflow JSON via API call
@@ -96,7 +101,7 @@ Enable faster development iteration via n8n API access, improve UX with inline k
 
 | Phase | Name | Requirements | Status |
 |-------|------|--------------|--------|
-| 6 | n8n API Access | API-01, API-02, API-03, API-04 | Pending |
+| 6 | n8n API Access | API-01, API-02, API-03, API-04 | Planning |
 | 7 | Socket Security | SEC-01, SEC-02, SEC-03, SEC-04 | Pending |
 | 8 | Inline Keyboard Infrastructure | KEY-01, KEY-02, KEY-03, KEY-04, KEY-05 | Pending |
 | 9 | Batch Operations | BAT-01, BAT-02, BAT-03, BAT-04, BAT-05, BAT-06 | Pending |
@@ -105,4 +110,4 @@ Enable faster development iteration via n8n API access, improve UX with inline k
 **v1.1 Coverage:** 22/22 requirements mapped
 
 ---
-*Updated: 2026-02-02*
+*Updated: 2026-02-03*