diff --git a/.github/actions/rust-cache/action.yml b/.github/actions/rust-cache/action.yml
index 2bd1d34..0323208 100644
--- a/.github/actions/rust-cache/action.yml
+++ b/.github/actions/rust-cache/action.yml
@@ -20,6 +20,9 @@ inputs:
   save-if:
     description: Allow publishing caches; PR consumers can restore without competing with the default branch
     default: "true"
+  restore-downloads:
+    description: Restore and populate shared downloads; disable only when an earlier call in this job already restored them
+    default: "true"
 
 outputs:
   cache-key:
@@ -90,6 +93,7 @@ runs:
         PY
     - name: Restore shared Cargo downloads
       id: downloads
+      if: inputs.restore-downloads == 'true'
       uses: actions/cache/restore@v4
       with:
         # Preserve Git source checkouts with their mtimes. Recreating them from
@@ -173,7 +177,7 @@ runs:
           echo "legacy-fallback-outcome=$legacy_outcome"
         } >> "$GITHUB_OUTPUT"
     - name: Populate complete downloads before sharing the cache
-      if: inputs.save-if == 'true' && steps.downloads.outputs.cache-hit != 'true'
+      if: inputs.save-if == 'true' && steps.downloads.outputs.cache-hit != 'true' && inputs.restore-downloads == 'true'
       shell: bash
       env:
         CACHE_OS: ${{ runner.os }}
@@ -193,7 +197,7 @@ runs:
             ;;
         esac
     - name: Save complete shared Cargo downloads
-      if: inputs.save-if == 'true' && steps.downloads.outputs.cache-hit != 'true'
+      if: inputs.save-if == 'true' && steps.downloads.outputs.cache-hit != 'true' && inputs.restore-downloads == 'true'
       uses: actions/cache/save@v4
       with:
         path: |
diff --git a/.github/workflows/linux-lua.yml b/.github/workflows/linux-lua.yml
index 2d70f4d..6868ca8 100644
--- a/.github/workflows/linux-lua.yml
+++ b/.github/workflows/linux-lua.yml
@@ -11,7 +11,7 @@ on:
   push:
     branches: [main]
   # Include docs, catalogs, assets and workflow edits: every PR gets test results.
-  # 草稿已跑完整矩阵，转为 Ready 而没有新提交时不重复申请七个原生 runner。
+  # 草稿已跑完整矩阵，转为 Ready 而没有新提交时不重复申请五个原生 runner。
   pull_request:
     types: [opened, synchronize, reopened]
   merge_group:
@@ -145,6 +145,18 @@ jobs:
           # PR merge-ref 缓存不与其他 PR 共享；只由默认分支维护可复用的依赖快照。
           revision: dependencies-v1
           save-if: ${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+      # 构建前计算两类缓存身份，避免生成文件进入 hashFiles 后改变原有缓存键。
+      # release 保留独立产物路径，但不重复恢复同一份源码下载。
+      - name: Restore macOS release workload
+        if: ${{ !cancelled() && runner.os == 'macOS' }}
+        uses: ./.github/actions/rust-cache
+        id: macos-release-cache
+        with:
+          key: native-release-check
+          target: target/release
+          revision: dependencies-v1
+          save-if: ${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+          restore-downloads: "false"
       - name: Prepare pinned Windows console runtime
         if: ${{ runner.os == 'Windows' }}
         shell: pwsh
@@ -163,6 +175,7 @@ jobs:
       - name: Check the release workspace
         if: ${{ !cancelled() && runner.os != 'macOS' }}
         run: cargo check --locked --workspace --release
+      # Mac 原生快照先于 release 检查保存，避免后者失败或取消丢掉已验证的编译结果。
       - name: Save compiled workload
         if: ${{ success() && steps.rust-cache.outputs.save-enabled == 'true' && steps.rust-cache.outputs.cache-hit != 'true' }}
         uses: actions/cache/save@v4
@@ -171,6 +184,15 @@ jobs:
             target/ci
             ${{ runner.os != 'macOS' && 'target/release' || '' }}
           key: ${{ steps.rust-cache.outputs.cache-key }}
+      - name: Check macOS release workspace
+        if: ${{ !cancelled() && runner.os == 'macOS' }}
+        run: cargo check --locked --workspace --release --timings
+      - name: Save macOS release workload
+        if: ${{ success() && steps.macos-release-cache.outputs.save-enabled == 'true' && steps.macos-release-cache.outputs.cache-hit != 'true' }}
+        uses: actions/cache/save@v4
+        with:
+          path: target/release
+          key: ${{ steps.macos-release-cache.outputs.cache-key }}
       - name: Upload native compilation timings
         if: ${{ always() }}
         uses: actions/upload-artifact@v4
@@ -181,60 +203,26 @@ jobs:
           compression-level: 0
           retention-days: 14
 
-  # The release check has no dependency on the test executable. Keeping it in
-  # the Intel test job added 11m33s after a 22m29s test/compile step in run
-  # 34856491552. Both jobs remain part of this reusable workflow's result, so
-  # the stable release aggregation still requires every check to succeed.
+  # 保留服务端已有的必需检查名称，但不为结果汇总再申请稀缺的 macOS runner。
+  # 只接受本轮完整原生矩阵成功；上游失败或跳过时不能把汇总直接标绿。
   macos-release-check:
-    needs: lint
-    if: ${{ inputs.windows_diagnostics_run == '' }}
+    needs: [lint, native-tests]
+    if: ${{ !cancelled() && inputs.windows_diagnostics_run == '' }}
     name: Release workspace (${{ matrix.os }})
     strategy:
       fail-fast: false
       matrix:
         include: ${{ fromJSON(needs.lint.outputs.release_matrix) }}
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 120
-    env:
-      PYTHONUTF8: "1"
-      CARGO_TERM_COLOR: always
-      RUST_BACKTRACE: "1"
-      RUST_TOOLCHAIN: "1.97.1"
+    runs-on: ubuntu-24.04
+    timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
-      - uses: actions/setup-python@v5
-        with:
-          python-version: "3.13"
-      - name: Require the AppKit SDK used by this PR
+      - name: Require this run's native and release checks
+        shell: python
+        env:
+          NATIVE_RESULT: ${{ needs.native-tests.result }}
         run: |
-          sdk_version="$(xcrun --sdk macosx --show-sdk-version)"
-          test "${sdk_version%%.*}" -ge 26
-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          toolchain: "1.97.1"
-      - uses: ./.github/actions/rust-cache
-        id: rust-cache
-        with:
-          key: native-release-check
-          target: target/release
-          revision: dependencies-v1
-          save-if: ${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
-      - name: Check the release workspace
-        run: cargo check --locked --workspace --release --timings
-      - name: Save compiled workload
-        if: ${{ success() && steps.rust-cache.outputs.save-enabled == 'true' && steps.rust-cache.outputs.cache-hit != 'true' }}
-        uses: actions/cache/save@v4
-        with:
-          path: target/release
-          key: ${{ steps.rust-cache.outputs.cache-key }}
-      - name: Upload release check compilation timings
-        if: ${{ always() }}
-        uses: actions/upload-artifact@v4
-        with:
-          name: release-check-timings-${{ matrix.os }}
-          path: target/cargo-timings
-          if-no-files-found: warn
-          compression-level: 0
-          retention-days: 14
+          import os
+          result = os.environ["NATIVE_RESULT"]
+          if result != "success":
+              raise SystemExit("Native validation did not succeed: " + result)
+          print("Both macOS release checks passed in the native matrix.")
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6ef5132..06fad6b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -131,7 +131,13 @@ compile check into a claim that UI tests or a packaged application were run.
 on `main`, together with Code Owner approval; see the
 [activation checklist](docs/project-constraints.md#server-side-activation).
 Draft and ready pull requests both run all five native platforms and both macOS
-release-profile compile checks. The required lint job validates the event and
+release-profile compile checks. Each macOS native job also runs its release check
+on the same runner, reusing the checkout, toolchain and source downloads while
+keeping the two compiled workloads in their existing separate caches. The two
+`Release workspace (<os>)` contexts are lightweight Linux result checks: they
+require this run's entire native matrix to succeed, not a previous run's result.
+The release compilation itself still runs natively on each Mac architecture.
+The required lint job validates the event and
 selects the matrix before requesting platform runners. Every required check must
 succeed before merging. Marking a draft ready without changing its commits does
 not repeat the matrix; source updates and reopen events run it again. Native CI
@@ -155,7 +161,7 @@ feature work; there is no routine `--skip-architecture` option.
 
 - 先读架构图、工程合同和决策记录；按职责拆分，不按行号切片。
 - 一个 PR 只做一件事；改动超过 1500 行源码（不计文档、lockfile、资源）`pr-size` 会失败，请拆分。
-- Draft 和 Ready PR 都先运行必需的格式检查和矩阵规划，再执行五平台原生测试及两项 macOS release 编译检查；十项必需检查全绿才能合并。提速使用共享缓存与并行测试，不省略平台或 doctest。
+- Draft 和 Ready PR 都先运行必需的格式检查和矩阵规划，再执行五平台原生测试及两项 macOS release 编译检查；每个 Mac 在同一 runner 完成两类检查，原有 release 检查名称由轻量结果汇总保留。十项必需检查全绿才能合并，不省略平台或 doctest。
 - 2000 行是现有仓库的防灾上限，800 行只提示审查，不是“大厂标准”。
 - 普通功能 PR 不得增加存量债务；有问题的规则可以修订，但要有反例、测试和维护者审批。
 - 新增核心抽象、依赖方向、持久化或线程模型改变要先说明设计，不强迫每个小修复写 ADR。
diff --git a/architecture/notes/scripts/ci/2026-09-25-shared-native-pr-cache.md b/architecture/notes/scripts/ci/2026-09-25-shared-native-pr-cache.md
index 8c827f7..1f862c4 100644
--- a/architecture/notes/scripts/ci/2026-09-25-shared-native-pr-cache.md
+++ b/architecture/notes/scripts/ci/2026-09-25-shared-native-pr-cache.md
@@ -1,5 +1,8 @@
 # Speed up native PR checks without dropping platform coverage
 
+Independent macOS runner placement superseded by
+[shared macOS runners](2026-09-27-shared-macos-runners.md).
+
 ## Status
 
 Implemented for review. The five native check names and two macOS release-check
diff --git a/architecture/notes/scripts/ci/2026-09-27-shared-macos-runners.md b/architecture/notes/scripts/ci/2026-09-27-shared-macos-runners.md
new file mode 100644
index 0000000..26f38f3
--- /dev/null
+++ b/architecture/notes/scripts/ci/2026-09-27-shared-macos-runners.md
@@ -0,0 +1,105 @@
+# Share macOS runners without dropping native or release checks
+
+## Status
+
+Implemented for review. Required check names and coverage are preserved;
+GitHub protection settings are unchanged. Hosted execution and timing of this
+revision remain to be measured.
+
+## Context
+
+Separating each Mac's native tests and release-profile compile check requests
+four macOS runners per PR. Parallel work can shorten execution, but an additional
+runner request can also become the critical path when capacity is scarce.
+
+## Evidence
+
+In [run 36314579470](https://github.com/Kuddev/pebrel/actions/runs/36314579470),
+the Intel release check executed for 3m16s after waiting 60m09s. The workflow
+finished after 66m21s. This is a scheduling problem, not an hour of compilation.
+
+That run's Windows ARM64 job missed its compiled target cache at 11:09:51 UTC.
+The same key's currently available default-branch entry was created at 11:31:52
+UTC on 2026-09-27. This establishes availability at those two observations,
+not the cause of any earlier eviction or a broken cache key. Do not invalidate
+existing caches as a speculative fix.
+
+GitHub's [cache documentation](https://docs.github.com/en/actions/reference/workflows-and-actions/dependency-caching)
+states that the cached paths participate in cache versioning. Combining the
+two target-directory lists would prevent reuse even if the visible key stayed
+unchanged. Its [job dependency contract](https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#jobsjob_idneeds)
+also requires an explicit status condition to continue after a failed dependency.
+
+## Decision
+
+- Run the original `cargo check --locked --workspace --release --timings` after
+  each Mac's native suite on the same runner. Retain the native architecture,
+  AppKit SDK requirement, pinned toolchain, test features and profile settings.
+  Linux and both Windows jobs retain their existing release checks.
+- Keep both `Release workspace (<os>)` names as short Ubuntu jobs. They depend
+  on lint and the current native matrix, and reject any result other than exact
+  `success`. They do not run Mac compilation on Linux, read older check results,
+  upload fabricated statuses, or require write permissions.
+- Preserve separate `native` and `native-release-check` cache keys, generations
+  and target paths. Both identities are computed before build/test commands can
+  generate additional manifests. The second cache action reuses downloads already
+  restored by the first action; other callers keep the default download behavior.
+- Save the fully successful native workload before beginning the Mac release
+  workload. A later release failure or cancellation need not discard that
+  completed warmup. Neither incomplete workload nor read-only PR consumers may
+  publish a compiled snapshot.
+- Retain all five platforms for draft/ready PRs and merge groups, both Python
+  suites, nextest, doctests, the product feature check and current cancellation
+  policy. Release/package callers and branch protection are not redesigned.
+
+## Rejected alternatives
+
+- Remove a platform, release compilation, doctests or assertions: changes the
+  required coverage rather than removing scheduling waste.
+- Keep requesting a separate Mac just to preserve a status name: a current-run
+  dependency check retains the required context without another scarce runner.
+- Introduce per-platform result artifacts or custom check-writing credentials:
+  unnecessary for the conservative rule that every native job must succeed.
+- Combine existing target archives or bump their generation: causes a cold-cache
+  transition without changing any compiler inputs or fixing a proven defect.
+- Delete remote caches or increase storage quota: not needed for this runner
+  change, and not evidence that cache retention has been solved.
+
+## Consequences
+
+Each full invocation requests two rather than four macOS runners. The two short
+result jobs still request Ubuntu runners, so this is not a reduction in the
+number of named checks. Each Mac's execution becomes sequential and can take
+longer on a cold cache; the change targets additional runner queue time.
+
+Both release contexts wait for the entire native matrix. An unrelated native
+failure also fails these summaries; the per-platform job logs retain the actual
+compile outcome. This is conservative and does not weaken merge acceptance.
+Native timing artifacts now include the Mac release compilation timings too.
+
+Existing cache footprint, dependency cold builds and default-branch seed timing
+remain relevant. This change does not promise a fixed CI duration or eliminate
+Windows ARM64 compilation cost.
+
+## Validation
+
+The six existing lint contract suites ran 62 tests on Windows: 61 passed and the
+existing POSIX-only cache-summary case was skipped. The workflow's actual Python
+result-check body accepts `success` and rejects failure, cancellation, skipped,
+empty and malformed results. Contracts retain full platform/event coverage,
+release compilation, default-branch-only cache publication and independent
+cache identities. Actionlint 1.7.12, workspace rustfmt, architecture checking
+against the PR base and the platform budget passed. Hosted cache restore/save
+and cross-platform timings remain pending a real workflow run.
+
+## Supersedes
+
+Only the separate macOS runner placement in
+[shared native PR caches](2026-09-25-shared-native-pr-cache.md). Its coverage,
+cache ownership and native test-runner decisions remain in force.
+
+## Revisit when
+
+Hosted measurements show sequential cold compilation exceeds the queue savings,
+macOS capacity changes, or a demonstrated cache-retention issue warrants its own
+bounded change. Compare queue, active execution and cache hit status separately.
diff --git a/scripts/tests/test_ci_cache.py b/scripts/tests/test_ci_cache.py
index 99a083a..2afad6c 100644
--- a/scripts/tests/test_ci_cache.py
+++ b/scripts/tests/test_ci_cache.py
@@ -195,6 +195,18 @@ class CacheIdentityTests(unittest.TestCase):
             body = source.split(f"- name: {step}", 1)[1].split("\n    - name:", 1)[0]
             self.assertIn("if: inputs.save-if == 'true' && steps.downloads.outputs.cache-hit != 'true'", body)
 
+    def test_second_workload_can_reuse_downloads_without_restoring_or_saving_them_again(self):
+        source = self.action_text()
+        option = source.split("\n  restore-downloads:\n", 1)[1].split("\noutputs:", 1)[0]
+        self.assertIn('default: "true"', option)
+        for step in ("Restore shared Cargo downloads", "Populate complete downloads before sharing the cache",
+                     "Save complete shared Cargo downloads"):
+            body = source.split(f"- name: {step}", 1)[1].split("\n    - name:", 1)[0]
+            condition = next(line for line in body.splitlines() if line.strip().startswith("if:"))
+            self.assertIn("inputs.restore-downloads == 'true'", condition)
+        target = source.split("- name: Restore compiled targets", 1)[1].split("\n    - name:", 1)[0]
+        self.assertNotIn("restore-downloads", target)
+
     @unittest.skipUnless(os.name == "nt", "Windows cache migration")
     def test_windows_migration_preserves_compiler_and_workload_boundaries(self):
         before = self.identity()
diff --git a/scripts/tests/test_ci_native_tests.py b/scripts/tests/test_ci_native_tests.py
index 383f8a5..14083b4 100644
--- a/scripts/tests/test_ci_native_tests.py
+++ b/scripts/tests/test_ci_native_tests.py
@@ -1,8 +1,11 @@
 from __future__ import annotations
 
+import os
 import subprocess
 import re
 from pathlib import Path
+import sys
+import textwrap
 import tomllib
 import unittest
 from unittest.mock import patch
@@ -43,11 +46,13 @@ class NativeSuiteTests(unittest.TestCase):
         platform_step = lint.split("Check platform cfg budget before native jobs", 1)[1].split("      - name:", 1)[0]
         self.assertNotIn("continue-on-error", platform_step)
         self.assertNotIn("--update", platform_step)
-        for job, output in (("native-tests", "native_matrix"),
-                            ("macos-release-check", "release_matrix")):
+        for job, output, needs in (
+            ("native-tests", "native_matrix", "needs: lint"),
+            ("macos-release-check", "release_matrix", "needs: [lint, native-tests]"),
+        ):
             body = workflow.split(f"\n  {job}:\n", 1)[1]
             body = re.split(r"\n  [a-z][a-z-]*:\n", body, maxsplit=1)[0]
-            self.assertIn("needs: lint", body)
+            self.assertIn(needs, body)
             self.assertIn(f"fromJSON(needs.lint.outputs.{output})", body)
             self.assertNotIn("pull_request.draft", body)
             self.assertNotIn("matrix.tier", body)
@@ -183,15 +188,59 @@ class NativeSuiteTests(unittest.TestCase):
     def test_native_caches_are_default_branch_snapshots_not_per_pr_uploads(self):
         root = Path(__file__).resolve().parents[2]
         workflow = (root / ".github/workflows/linux-lua.yml").read_text(encoding="utf-8")
-        for job in ("native-tests", "macos-release-check"):
-            body = workflow.split(f"\n  {job}:\n", 1)[1]
-            body = re.split(r"\n  [a-z][a-z-]*:\n", body, maxsplit=1)[0]
-            self.assertIn("revision: dependencies-v1", body)
-            self.assertIn("save-if: ${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}", body)
-            save = body.split("- name: Save compiled workload", 1)[1].split("      - name:", 1)[0]
-            self.assertIn("success() && steps.rust-cache.outputs.save-enabled == 'true'", save)
+        native = workflow.split("\n  native-tests:\n", 1)[1].split("\n  macos-release-check:\n", 1)[0]
+        for cache_id, save_name in (("rust-cache", "Save compiled workload"),
+                                   ("macos-release-cache", "Save macOS release workload")):
+            cache = native.split(f"id: {cache_id}\n", 1)[1].split("\n      - ", 1)[0]
+            self.assertIn("revision: dependencies-v1", cache)
+            self.assertIn("save-if: ${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}", cache)
+            save = native.split(f"- name: {save_name}", 1)[1].split("\n      - ", 1)[0]
+            self.assertIn(f"success() && steps.{cache_id}.outputs.save-enabled == 'true'", save)
             self.assertNotIn("always()", save)
-            self.assertIn("steps.rust-cache.outputs.cache-hit != 'true'", save)
+            self.assertIn(f"steps.{cache_id}.outputs.cache-hit != 'true'", save)
+        self.assertLess(native.index("Test complete workspace"), native.index("Save compiled workload"))
+        self.assertLess(native.index("Restore macOS release workload"), native.index("Test complete workspace"))
+        self.assertLess(native.index("Save compiled workload"), native.index("Check macOS release workspace"))
+        release_cache = native.split("- name: Restore macOS release workload", 1)[1].split("\n      - ", 1)[0]
+        self.assertIn("key: native-release-check", release_cache)
+        self.assertIn("target: target/release", release_cache)
+        self.assertIn('restore-downloads: "false"', release_cache)
+
+    def test_macos_release_compilation_reuses_the_native_runner(self):
+        root = Path(__file__).resolve().parents[2]
+        workflow = (root / ".github/workflows/linux-lua.yml").read_text(encoding="utf-8")
+        native = workflow.split("\n  native-tests:\n", 1)[1].split("\n  macos-release-check:\n", 1)[0]
+        release = native.split("- name: Check macOS release workspace", 1)[1].split("\n      - ", 1)[0]
+        self.assertIn("if: ${{ !cancelled() && runner.os == 'macOS' }}", release)
+        self.assertIn("run: cargo check --locked --workspace --release --timings", release)
+        self.assertNotIn("continue-on-error", native)
+        self.assertLess(native.index("Require the AppKit SDK"), native.index("Check macOS release workspace"))
+        self.assertLess(native.index("Restore macOS release workload"), native.index("Check macOS release workspace"))
+        self.assertLess(native.index("Check macOS release workspace"), native.index("Save macOS release workload"))
+
+    def test_release_required_contexts_reject_failed_or_missing_native_results(self):
+        root = Path(__file__).resolve().parents[2]
+        workflow = (root / ".github/workflows/linux-lua.yml").read_text(encoding="utf-8")
+        report = workflow.split("\n  macos-release-check:\n", 1)[1]
+        self.assertIn("needs: [lint, native-tests]", report)
+        self.assertIn("if: ${{ !cancelled() && inputs.windows_diagnostics_run == '' }}", report)
+        self.assertIn("name: Release workspace (${{ matrix.os }})", report)
+        self.assertIn("fromJSON(needs.lint.outputs.release_matrix)", report)
+        self.assertIn("runs-on: ubuntu-24.04", report)
+        self.assertIn("shell: python", report)
+        self.assertIn("NATIVE_RESULT: ${{ needs.native-tests.result }}", report)
+        self.assertNotIn("uses:", report)
+        self.assertNotIn("continue-on-error", report)
+        script = textwrap.dedent(report.split("        run: |\n", 1)[1])
+        for result in ("success", "failure", "cancelled", "skipped", "", "success\n"):
+            with self.subTest(result=result):
+                completed = subprocess.run(
+                    [sys.executable, "-c", script],
+                    env={**os.environ, "NATIVE_RESULT": result},
+                    capture_output=True, text=True, encoding="utf-8", check=False,
+                )
+                self.assertEqual(completed.returncode, 0 if result == "success" else 1,
+                                 completed.stderr)
 
     def test_fast_test_profile_preserves_runtime_checks_and_resets_named_overrides(self):
         root = Path(__file__).resolve().parents[2]