diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index cf4617b..6f72000 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -7,6 +7,10 @@ on:
 permissions:
   contents: write
 
+concurrency:
+  group: release-${{ github.ref }}
+  cancel-in-progress: false
+
 env:
   RELEASE_NOTES_DIR: docs/releases
 
@@ -33,28 +37,33 @@ jobs:
       - name: Build Core archive and Stable product manifest
         run: |
           test "$(git describe --tags --exact-match)" = "${GITHUB_REF_NAME}"
+          remote_tag_commit="$(git ls-remote origin "refs/tags/${GITHUB_REF_NAME}^{}" | awk '{print $1}')"
+          test "${remote_tag_commit}" = "${GITHUB_SHA}"
           cp scripts/evozeus-install-preflight.mjs evozeus-install-preflight.mjs
           shasum -a 256 evozeus-install-preflight.mjs > evozeus-install-preflight.mjs.sha256
           git archive --format=tar.gz --prefix="EvoZeus-${GITHUB_REF_NAME}/" -o "evozeus-${GITHUB_REF_NAME}.tar.gz" "${GITHUB_REF_NAME}"
           shasum -a 256 "evozeus-${GITHUB_REF_NAME}.tar.gz" > "evozeus-${GITHUB_REF_NAME}.tar.gz.sha256"
           node scripts/build-stable-product-manifest.mjs --input channels/stable-release-input.json --core-archive "evozeus-${GITHUB_REF_NAME}.tar.gz" --core-commit "${GITHUB_SHA}" --output evozeus-product-stable.json
-      - name: Verify immutable Releases are enabled
-        env:
-          GH_TOKEN: ${{ github.token }}
-        run: |
-          immutable_releases_enabled="$(gh api "repos/${GITHUB_REPOSITORY}/immutable-releases" --jq '.enabled')"
-          test "${immutable_releases_enabled}" = "true"
       - name: Create or reuse immutable Release draft
+        id: release_draft
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
           release_state="$(gh release view "${GITHUB_REF_NAME}" --json isDraft,isImmutable --jq '[.isDraft,.isImmutable] | @tsv' 2>/dev/null || true)"
           if [ -z "${release_state}" ]; then
             gh release create "${GITHUB_REF_NAME}" --verify-tag --draft --title "EvoZeus ${GITHUB_REF_NAME}" --notes-file "${RELEASE_NOTES_DIR}/${GITHUB_REF_NAME}.md"
-          else
-            test "${release_state}" = $'true\tfalse'
+            publish_required="true"
+          elif [ "${release_state}" = $'true\tfalse' ]; then
             gh release edit "${GITHUB_REF_NAME}" --title "EvoZeus ${GITHUB_REF_NAME}" --notes-file "${RELEASE_NOTES_DIR}/${GITHUB_REF_NAME}.md"
+            publish_required="true"
+          elif [ "${release_state}" = $'false\tfalse' ]; then
+            gh release delete "${GITHUB_REF_NAME}" --yes
+            exit 1
+          else
+            test "${release_state}" = $'false\ttrue'
+            publish_required="false"
           fi
+          echo "publish_required=${publish_required}" >> "${GITHUB_OUTPUT}"
       - name: Upload and verify the complete Release asset set
         env:
           GH_TOKEN: ${{ github.token }}
@@ -66,7 +75,9 @@ jobs:
             "evozeus-${GITHUB_REF_NAME}.tar.gz.sha256"
             evozeus-product-stable.json
           )
-          gh release upload "${GITHUB_REF_NAME}" "${assets[@]}" --clobber
+          if [ "${{ steps.release_draft.outputs.publish_required }}" = "true" ]; then
+            gh release upload "${GITHUB_REF_NAME}" "${assets[@]}" --clobber
+          fi
           asset_count="$(gh release view "${GITHUB_REF_NAME}" --json assets --jq '.assets | length')"
           test "${asset_count}" -eq "${#assets[@]}"
           for asset in "${assets[@]}"; do
@@ -75,8 +86,15 @@ jobs:
             test "${actual_digest}" = "${expected_digest}"
           done
       - name: Publish and lock the verified immutable Release
+        if: steps.release_draft.outputs.publish_required == 'true'
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
+          remote_tag_commit="$(git ls-remote origin "refs/tags/${GITHUB_REF_NAME}^{}" | awk '{print $1}')"
+          test "${remote_tag_commit}" = "${GITHUB_SHA}"
           gh release edit "${GITHUB_REF_NAME}" --draft=false --latest
-          test "$(gh release view "${GITHUB_REF_NAME}" --json isDraft,isImmutable --jq '[.isDraft,.isImmutable] | @tsv')" = $'false\ttrue'
+          release_state="$(gh release view "${GITHUB_REF_NAME}" --json isDraft,isImmutable --jq '[.isDraft,.isImmutable] | @tsv' 2>/dev/null || true)"
+          if [ "${release_state}" = $'false\tfalse' ]; then
+            gh release delete "${GITHUB_REF_NAME}" --yes
+          fi
+          test "${release_state}" = $'false\ttrue'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c1d280..8281fd8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,7 @@
 
 ### Verification
 
-- Release workflow regressions enforce the repository immutable setting, draft creation, upload-before-publish ordering, the exact five-asset set, per-asset digest verification, and final `isImmutable=true` state.
+- Release workflow regressions serialize duplicate tag runs, idempotently re-audit an existing immutable Release, verify remote Tag identity before build and publication, enforce the exact five-asset set and per-asset digests, and require final `isImmutable=true`; a published mutable Release is deleted and the job fails.
 - The v0.5.1 candidate must repeat the single-UAT install, Doctor, correction/neutral/ambiguous Hook checks, zero-persistence check, and archive-to-tag tree identity audit before Stable completion.
 
 ## [v0.5.0] - 2026-08-04
diff --git a/docs/releases/v0.5.1.md b/docs/releases/v0.5.1.md
index 7948912..6131a1b 100644
--- a/docs/releases/v0.5.1.md
+++ b/docs/releases/v0.5.1.md
@@ -6,15 +6,15 @@ EvoZeus v0.5.1 保留 v0.5.0 的 Core Lesson runtime、CoEvolve v0.15.0 与 cano
 
 ## 发布修复
 
-Release workflow 从“先发布、再上传”升级为五段 fail-closed 事务：
+Release workflow 从“先发布、再上传”升级为五段发布事务；资产完整性路径 fail-closed，immutability 配置漂移采用 bounded rollback：
 
-1. 在创建正式入口前确认仓库已启用 immutable Releases。
-2. 创建或复用 draft Release，验证 Tag，并同步正式标题与 Release Notes。
+1. 同一 Tag 的重复任务串行执行；后续任务对已发布 immutable Release 做幂等复核。
+2. 创建或复用 draft Release，验证 Tag，并同步正式标题与 Release Notes；恢复任务发现遗留可变 Release 时先删除并失败。
 3. 上传 preflight、两份 checksum、Core archive 和 Stable product manifest 共五个资产。
 4. 核对精确资产集合，并将每个本地 SHA-256 与 GitHub asset digest 逐项比较。
-5. 全部通过后发布，随后断言 `isDraft=false` 且 `isImmutable=true`。
+5. 构建前和发布前均验证远端 Tag Commit；全部通过后发布并断言 `isDraft=false`、`isImmutable=true`。若仓库配置漂移产生可变 Release，执行补偿删除并使任务失败。
 
-任何大文件上传失败都会把 Release 保留在 draft，正式入口不会出现缺失资产的版本。
+任何大文件上传失败都会把 Release 保留在 draft，正式入口不会出现缺失资产的版本。GitHub Actions 内置令牌无仓库 Administration 读取权限，因此 immutable 状态在发布后由 Release 自身状态验证，并对可变结果执行补偿删除；这属于 bounded rollback，服务端 immutable setting 仍是正式发布的治理前置条件。
 
 ## 版本组合
 
diff --git a/scripts/release-notes-layout.test.mjs b/scripts/release-notes-layout.test.mjs
index 3cfdb36..62fc56a 100644
--- a/scripts/release-notes-layout.test.mjs
+++ b/scripts/release-notes-layout.test.mjs
@@ -32,21 +32,23 @@ test("resolves tag Release Notes from docs/releases", () => {
 
 test("uploads and verifies every Release asset before immutable publication", () => {
   const workflow = readFileSync(join(ROOT, ".github", "workflows", "release.yml"), "utf8");
-  const verifyImmutableSetting = workflow.indexOf("immutable-releases");
   const createDraft = workflow.indexOf("gh release create");
   const uploadAssets = workflow.indexOf("gh release upload");
   const verifyDigest = workflow.indexOf("actual_digest=");
   const publishRelease = workflow.indexOf("gh release edit", uploadAssets);
   const assetBlock = workflow.match(/assets=\(\n([\s\S]*?)\n\s*\)/);
 
-  assert.ok(verifyImmutableSetting >= 0);
-  assert.ok(createDraft > verifyImmutableSetting);
+  assert.match(workflow, /concurrency:\n\s+group: release-\$\{\{ github\.ref \}\}\n\s+cancel-in-progress: false/);
+  assert.ok(createDraft >= 0);
   assert.ok(uploadAssets > createDraft);
   assert.ok(verifyDigest > uploadAssets);
   assert.ok(publishRelease > verifyDigest);
   assert.match(workflow.slice(createDraft, uploadAssets), /--verify-tag --draft/);
   assert.match(workflow.slice(createDraft, uploadAssets), /gh release edit[^\n]+--notes-file/);
-  assert.match(workflow.slice(verifyImmutableSetting, createDraft), /test "\$\{immutable_releases_enabled\}" = "true"/);
+  assert.match(workflow.slice(createDraft, uploadAssets), /elif \[ "\$\{release_state\}" = \$'false\\tfalse' \]; then/);
+  assert.match(workflow.slice(createDraft, uploadAssets), /gh release delete "\$\{GITHUB_REF_NAME\}" --yes\n\s+exit 1/);
+  assert.match(workflow.slice(createDraft, uploadAssets), /test "\$\{release_state\}" = \$'false\\ttrue'/);
+  assert.match(workflow.slice(createDraft, uploadAssets), /publish_required="false"/);
   assert.ok(assetBlock);
   assert.deepEqual(
     assetBlock[1].trim().split("\n").map((line) => line.trim().replace(/^"|"$/g, "")),
@@ -59,9 +61,13 @@ test("uploads and verifies every Release asset before immutable publication", ()
     ],
   );
   assert.match(workflow, /test "\$\{asset_count\}" -eq "\$\{#assets\[@\]\}"/);
+  assert.match(workflow, /steps\.release_draft\.outputs\.publish_required/);
+  assert.equal([...workflow.matchAll(/git ls-remote origin/g)].length, 2);
   assert.match(workflow, /isDraft,isImmutable/);
   assert.match(workflow.slice(publishRelease), /--draft=false --latest/);
-  assert.match(workflow.slice(publishRelease), /false\\ttrue/);
+  assert.match(workflow.slice(publishRelease), /if \[ "\$\{release_state\}" = \$'false\\tfalse' \]/);
+  assert.match(workflow.slice(publishRelease), /gh release delete "\$\{GITHUB_REF_NAME\}" --yes/);
+  assert.match(workflow.slice(publishRelease), /test "\$\{release_state\}" = \$'false\\ttrue'/);
 });
 
 test("keeps current product metadata and Release Notes aligned", () => {