P4a archive: move plan to history + update index/README/tasks

blueprint: mark P4a as completed, compress to one-line summary
history: add 20260509_p4a_external_surface_freeze archive

Author: Li-Sanze

.sopify-skills/blueprint/README.md

@@ -14,7 +14,7 @@
 
 <!-- sopify:auto:focus:start -->
 - 当前活动 plan：暂无。
-- history 归档：已可用；最近归档为 `../history/2026-05/20260508_p3b_perimeter_cleanup`。
+- history 归档：已可用；最近归档为 `../history/2026-05/20260509_p4a_external_surface_freeze`。
 <!-- sopify:auto:focus:end -->
 
 ## 深入阅读入口
@@ -27,5 +27,5 @@
 - [Sopify 最小协议规范 (Protocol v0)](./protocol.md)
 - [Skill 标准对齐蓝图](./skill-standards-refactor.md)
 - [变更历史](../history/index.md)
-- 最近归档：`../history/2026-05/20260508_p3b_perimeter_cleanup`
+- 最近归档：`../history/2026-05/20260509_p4a_external_surface_freeze`
 <!-- sopify:auto:read-next:end -->

.sopify-skills/blueprint/tasks.md

@@ -20,7 +20,7 @@
 | P2 | local_action_contracts | P1.5 | 已完成。在主体已绑定前提下收敛局部动作 contract |
 | P3a | contract_aligned_cleanup | P2 | 已完成。以 protocol/validator 已稳定为前提，清理 runtime 旧 contract 面 |
 | P3b | perimeter_cleanup | P3a | 已完成。外围面清理：release gate 修复、CHANGELOG 去文件列表化、tests 分类、旧概念清理 |
-| P4a | external_surface_freeze | P3b | 薄切片：冻结不可删外部消费面 keep-list |
+| P4a | external_surface_freeze | P3b | 已完成。薄切片：冻结不可删外部消费面 keep-list |
 | P4b | runtime_surface_consolidation | P4a | Runtime 结构性减重（26K→<20K），先删后并 |
 | P4c | host_consumption_governance | P4a | 宿主只消费 contract，不定义 truth |
 
@@ -48,15 +48,9 @@
 
 ✅ 已完成。Release gate 修复、CHANGELOG 压缩、tests 分类标注、replay/workflow-learning 下线、README 首屏降噪、旧概念清理。归档：`history/2026-05/20260508_p3b_perimeter_cleanup/`
 
-### P4a: External Surface Freeze
+### P4a: External Surface Freeze（已完成）
 
-薄切片。列出不可删除的外部消费面 keep-list，作为 P4b 减重的红线边界。
-
-- 枚举 keep-list：protocol.md、gate contract（gate_receipt schema）、handoff/receipt machine truth fields、archive truth（ArchiveCheckResult / ArchiveApplyResult）、install.sh/install.ps1 contract（SOURCE_CHANNEL, SOURCE_REF）、builtin_catalog.py 导出接口（freeze 指接口契约形态——schema / entry_kind / metadata contract，不指具体 skill 枚举或文件字节；能力上下线属内容变更，不违反 freeze）、skill_eval baseline/SLO
-- **冻结 persistence surface 分类**：keep-list 覆盖到目录级别（参照 design.md "Persistence Surface 分层"表），明确哪些目录属于长期知识/主链真相/凭证/可删派生，作为 P4b 减重和 P4c 宿主消费治理的红线
-- 输出：design.md 加 "Frozen External Surface" 表（与 Persistence Surface 分层互补——后者分类所有持久化面，Frozen 表只冻结外部消费面的 keep-list；不重复造表）
-- **Output rendering fields 分类**：逐字段审计 `runtime/output.py` 渲染层，分三类——machine truth projection（handoff/receipt 投影）/ human hint（Next 等面向人的提示）/ internal taxonomy leak（gate_status 等不应默认暴露的内部术语）。审计结果写入 Frozen External Surface 表，作为 P4c output contract convergence 的输入
-- 不写代码，纯边界确认
+✅ 已完成。Frozen External Surface keep-list（15 条）+ Output Rendering Audit（20 条字段分类 + 5 个已知热点）。纯文档变更，不写运行代码。归档：`history/2026-05/20260509_p4a_external_surface_freeze/`
 
 ### P4b: Runtime Surface Consolidation
 

…4a_external_surface_freeze/background.md …4a_external_surface_freeze/background.md.sopify-skills/plan/20260509_p4a_external_surface_freeze/background.md renamed to .sopify-skills/history/2026-05/20260509_p4a_external_surface_freeze/background.md .sopify-skills/plan/20260509_p4a_external_surface_freeze/background.md renamed to .sopify-skills/history/2026-05/20260509_p4a_external_surface_freeze/background.md

@@ -4,6 +4,7 @@
 
 ## 索引
 
+- `2026-05-09` [`20260509_p4a_external_surface_freeze`](2026-05/20260509_p4a_external_surface_freeze/) - standard - P4a External Surface Freeze: Frozen External Surface keep-list（15 条）+ Output Rendering Audit（20 条字段分类）
 - `2026-05-08` [`20260508_p3b_perimeter_cleanup`](2026-05/20260508_p3b_perimeter_cleanup/) - standard - 任务清单: P3b Perimeter Cleanup
 - `2026-05-08` [`20260507_p3a_contract_aligned_surface_cleanup`](2026-05/20260507_p3a_contract_aligned_surface_cleanup/) - standard - P3a Contract-Aligned Surface Cleanup: execution routing 收敛 + knowledge_sync audit trail + dead path cleanup (-88 LOC) + Runtime 减重剥离为 Px
 - `2026-05-07` [`20260506_p2_local_action_contracts`](2026-05/20260506_p2_local_action_contracts/) - standard - P2 Local Action Contracts: subject binding 泛化 + side_effect_delta schema + action-effect canonical pairing（admission contract 闭合）

…09_p4a_external_surface_freeze/design.md …09_p4a_external_surface_freeze/design.md.sopify-skills/plan/20260509_p4a_external_surface_freeze/design.md renamed to .sopify-skills/history/2026-05/20260509_p4a_external_surface_freeze/design.md .sopify-skills/plan/20260509_p4a_external_surface_freeze/design.md renamed to .sopify-skills/history/2026-05/20260509_p4a_external_surface_freeze/design.md

@@ -0,0 +1,29 @@
+version: 1
+mode: "observe_only"
+selection_policy: "explicit_only"
+priority_policy: "heuristic_v1"
+priority_fallback: "p2"
+plans:
+  - plan_id: "20260418_cross_review_engine"
+    snapshot:
+      path: ".sopify-skills/plan/20260418_cross_review_engine"
+      title: "Cross-Review 独立内核方案"
+      level: "standard"
+      topic_key: "cross_review_engine"
+      lifecycle_state: "active"
+      created_at: "2026-05-04T14:45:24+00:00"
+    governance:
+      priority: null
+      priority_source: null
+      priority_confirmed_at: null
+      status: "deferred"
+      note: ""
+    advice:
+      suggested_priority: "p2"
+      suggested_source: "heuristic_v1"
+      suggested_reason:
+        - "未识别明确紧急或降级信号，先按默认建议观察"
+      suggested_at: "2026-05-05T11:12:58+00:00"
+    meta:
+      source: "runtime_backfill"
+      updated_at: "2026-05-05T11:12:58+00:00"