docs(01-01): complete WorkflowStateManager plan

Summary:
- WorkflowStateManager with atomic write and backup rotation
- 90% test coverage (20 tests)
- 5 min execution time

State updates:
- Plan counter advanced to 3
- Progress: 67% (2/3 plans complete)
- Requirements marked complete: PIPE-02, REL-01

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -2,15 +2,16 @@
 gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
-status: planning
-stopped_at: Plan 02 completed (Core Pipeline Schemas)
-last_updated: "2026-03-13T09:09:01Z"
-last_activity: 2026-03-13 — Plan 02 completed (Core Pipeline Schemas)
+current_plan: 3
+status: executing
+stopped_at: Completed 01-01 WorkflowStateManager
+last_updated: "2026-03-13T09:19:17.560Z"
+last_activity: 2026-03-13
 progress:
   total_phases: 4
   completed_phases: 0
   total_plans: 3
-  completed_plans: 1
+  completed_plans: 2
   percent: 8
 ---
 
@@ -26,10 +27,10 @@ See: .planning/PROJECT.md (updated 2026-03-13)
 ## Current Position
 
 Phase: 1 of 4 (Foundation)
-Current Plan: 2 of 3 in current phase
+Current Plan: 3
 Total Plans in Phase: 3
 Status: Executing
-Last activity: 2026-03-13 — Plan 02 completed (Core Pipeline Schemas)
+Last activity: 2026-03-13
 
 Progress: [█░░░░░░░░░] 8%
 
@@ -54,6 +55,7 @@ Progress: [█░░░░░░░░░] 8%
 - Trend: -
 
 *Updated after each plan completion*
+| Phase 01-foundation P01 | 5 | 3 tasks | 3 files |
 
 ## Accumulated Context
 
@@ -66,6 +68,8 @@ Recent decisions affecting current work:
 - [01-02]: 使用 Pydantic v2 作为 Schema 验证框架
 - [01-02]: WorkflowState 包含步骤状态管理方法
 - [01-02]: 创建 pytest.ini 配置 pythonpath
+- [Phase 01-01]: Follow gsd-openclaw atomic write pattern for crash-safe state persistence
+- [Phase 01-01]: Return None instead of raising exception when no state file exists
 
 ### Pending Todos
 
@@ -81,6 +85,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-03-13T09:09:01Z
-Stopped at: Plan 02 completed (Core Pipeline Schemas)
-Resume file: .planning/phases/01-foundation/01-02-SUMMARY.md
+Last session: 2026-03-13T09:19:17.559Z
+Stopped at: Completed 01-01 WorkflowStateManager
+Resume file: None