feat(skills): workspace W>G resolve with reserved core protection

Add hooks/_runtime/skill-resolution.cjs as the single Owner for
workspace-namespace skills over global ~/.agents/skills, block reserved
skill ids from W override, bind BundleDecision selected identity via
resolutionPlan, carve workspace skills out of managed/control-plane
paths, expose devcodex skill resolve, and gate with test:skill-resolve
plus validation-manifest nodes on fast/full routes.

Author: rockyshi1993

README.md

@@ -203,8 +203,13 @@ GlobalOnlyHostConfigModeV1 与 GlobalOnlyWorkspaceCleanModeV1 将宿主配置、
 
 <workspace>/
 └── .devcodex/      ← workspace-namespace 的 Profile、记忆、报告与运行态
+    └── workspace/
+        ├── profile/   ← 事实 base
+        └── skills/    ← 可选自定义 Skill（W；非 reserved 时 W>G，见 skill-resolution）
 ```
 
+自定义 Skill 只写 `<workspace>/.devcodex/workspace/skills/<id>/SKILL.md`（一次配置，经 DevCodex resolve 五宿主共用）；**不要**改 `~/.agents/skills` 或五宿主 home 树作扩展。强制核 skill（如 `compliance`/`cp-gate`）禁止 W 覆盖。诊断：`devcodex skill resolve <id> --json`；探针：`npm run test:skill-resolve`。
+
 bare `devcodex init/update` 只管理 `.devcodex`。若当前路径没有可复用的祖先 workspace marker，且不存在旧版项目运行态，首次执行会原子创建 `.devcodex/layout.json` 并采用 `workspace-namespace`；若祖先已存在有效 marker，则沿用祖先 owner；本地 marker 非法时返回 `WORKSPACE_LAYOUT_INVALID`，旧 `.devcodex/profile`、`.memory` 等运行态存在时返回 `WORKSPACE_LAYOUT_MIGRATION_REQUIRED`，不会静默切换目录，需先执行 `devcodex migrate-layout plan/apply`。`devcodex init --claude`、`devcodex init --codex`、`--host`、`--gemini`、`--grok`、裸 `devcodex uninstall` 以及 `uninstall --host grok` 首批均返回结构化错误 `CLI_HOST_CONFIG_GLOBAL_ONLY`。安装与更新错误会指向 npm 全局命令；卸载错误会明确首批不支持自动删除用户级配置。现有工作区宿主文件不会被自动迁移、覆盖或删除；删除前仍需用户明确确认。
 
 Grok 全局刷新会先识别所有同名 plugin identity：受管 canonical、已知 legacy 与受管恢复来源会经官方 `grok plugin uninstall/install` 收敛为一个 canonical identity；任意未知同名来源会在写入前阻断。收敛前保留配置、registry 证据及 source/installed 字节快照，不直接改写 Grok registry，也不自动删除旧工作区 source。

changelogs/unreleased.md

@@ -5,6 +5,7 @@
 
 ## 当前未发布实现候选
 
+- **工作区 Skill 双层 resolve（S2 / W>G）**：新增 `hooks/_runtime/skill-resolution.cjs`（唯一 Owner）：`workspace-namespace` 下 `.devcodex/workspace/skills` 优先于 `~/.agents/skills`，**reserved** skill id 禁止 W 覆盖；同次 digest/content 契约；`profile_skill_plan` / `BundleDecisionV2` 附加 `resolutionPlan` 并改写 selected source identity；Hook 对 workspace-skill 做 managed/control-plane carve-out；CLI `devcodex skill resolve`；`npm run test:skill-resolve`（含 hook 路径矩阵；并入 `test:control-plane`）；`validation-manifest` 节点 `skill-resolve` + `skill-resolution-hook-paths` 进入 fast/full/profile-deploy/package-release；apply 目标禁入 W 树。需求：`双层Skill用户优先与意图加载` CP2 v1.2 S2 / CP3。
 - **SourceExistenceVerificationGate（规范吸纳防复发）**：`spec-absorption` 强制在输出「可吸纳」前对 source-root 做同名/近邻存在性验证；台账 `open/pending absorption` 不得单独成 absorb。`AbsorptionCandidateMatrixV1` 增加 `sourceExistence`；planner 阻断 `unverified` 与 `present/equivalent-covered` 的 absorb；并列「可关账清单」。负向：ledger-status-only。验证：`node scripts/plan-absorption-candidates.js --self-test`、`npm run test:residual-absorption-controls`、V81 needles。
 - **ExecutableAbsorption + ProbeNecessity（假吸纳禁止）**：吸纳必须可执行——`enforcementLevel` 不得为 checklist-only/none；每条 absorb 必填 `probeNecessity`（required/conditional/not-required/forbidden、alwaysOnImpact、复杂度与误报）。只写 Skill 正文或「以后再补探针」不得 ready/absorbed。分类器 `classifyExecutableAbsorptionSample`。验证：planner self-test + residual + V81。
 - **可执行吸纳主包 A 实施（R1～R4 + T2）**：`ProgressReportFastPath`（skill-gap/compliance/SC16）；`TaskPhaseProjectionGate`（cp-gate/user-visible-output）；`ClosedArtifactNoReviveGate`（cp-gate）；`FormalRerunLightClassify` + `FindingObjectLayer`（consumer-validation）。探针：`scripts/lib/executable-absorption-gates.js` + `npm run test:executable-absorption-gates`（并入 host-parity / control-plane）。

hooks/_runtime/lifecycle.cjs

@@ -861,6 +861,15 @@ function toControlPlaneRelPath(target) {
 
 function isControlPlaneSourcePath(target, state) {
   if (!target || isDevCodexManagedPath(target, state)) return false
+  // Workspace custom skills must never be treated as package control-plane skills/
+  try {
+    const { isWorkspaceSkillPath } = require('./skill-resolution.cjs')
+    if (isWorkspaceSkillPath(resolveRelativeToContext(target), { cwd: CONTEXT_ROOT || WORKSPACE_ROOT })) {
+      return false
+    }
+  } catch {
+    /* skill-resolution optional during partial deploys */
+  }
   const rel = toControlPlaneRelPath(target)
   return CONTROL_PLANE_SOURCE_RE.test(rel)
 }
@@ -943,6 +952,15 @@ function isActiveDevCodexNamespacePath(target, state) {
 
 function isDevCodexManagedPath(target, state) {
   if (!target) return false
+  // Carve-out: workspace skills are user-editable extensions, not managed G/runtime state
+  try {
+    const { isWorkspaceSkillPath } = require('./skill-resolution.cjs')
+    if (isWorkspaceSkillPath(resolveRelativeToContext(target), { cwd: CONTEXT_ROOT || WORKSPACE_ROOT })) {
+      return false
+    }
+  } catch {
+    /* optional */
+  }
   const rel = toWorkspaceRelativePath(target)
   if (DEVCODEX_DEPLOYMENT_PATH_RE.test(rel)) return true
   return isActiveDevCodexNamespacePath(target, state)