fix(ci): isolate coverage checkout by run attempt

.github/workflows/opencode-review-dispatch.yml

@@ -479,11 +479,11 @@ jobs:
       - name: Prepare pull request merge tree for coverage measurement
         env:
           COVERAGE_SOURCE_ARCHIVE: ${{ runner.temp }}/opencode-coverage-artifact/opencode-coverage-source.tar
-          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/pr-head
+          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/opencode-coverage-${{ github.run_id }}-${{ github.run_attempt }}
         run: |
           set -euo pipefail
-          rm -rf "$COVERAGE_SOURCE_WORKDIR"
-          mkdir -p "$COVERAGE_SOURCE_WORKDIR"
+          # Each attempt owns a fresh tree; never delete another job's checkout.
+          mkdir "$COVERAGE_SOURCE_WORKDIR"
           # The archive contains pull-request-controlled paths. Validate every
           # member before extraction so a symlink, hardlink, device, FIFO, or
           # traversal path cannot redirect a later trusted host-side parser.
@@ -533,7 +533,7 @@ jobs:
         env:
           PR_BASE_SHA: ${{ needs.validate-pr-metadata.outputs.base_sha }}
           PR_HEAD_SHA: ${{ needs.validate-pr-metadata.outputs.head_sha }}
-          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/pr-head
+          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/opencode-coverage-${{ github.run_id }}-${{ github.run_attempt }}
           # Dependency resolution may consume wheels/packages, but PR-defined
           # install/build hooks are never executed implicitly.
           UV_NO_BUILD: "1"
@@ -568,7 +568,7 @@ jobs:
       - name: Enforce changed-file syntax gate
         env:
           PR_BASE_SHA: ${{ needs.validate-pr-metadata.outputs.base_sha }}
-          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/pr-head
+          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/opencode-coverage-${{ github.run_id }}-${{ github.run_attempt }}
         run: |
           set -euo pipefail
           # Deterministic per-file syntax check on the PR's changed files. The
@@ -600,7 +600,7 @@ jobs:
         env:
           PR_BASE_SHA: ${{ needs.validate-pr-metadata.outputs.base_sha }}
           PR_HEAD_SHA: ${{ needs.validate-pr-metadata.outputs.head_sha }}
-          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/pr-head
+          COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/opencode-coverage-${{ github.run_id }}-${{ github.run_attempt }}
           # Apply wheel-only resolution in the same step that consumes
           # pull-request dependency metadata. A value on an earlier step does
           # not cross the GitHub Actions step boundary.

tests/test_opencode_agent_contract.py

@@ -568,7 +568,13 @@ def test_opencode_target_coverage_materializes_only_after_authorized_dispatch():
     assert "GH_TOKEN:" not in measure_step
     assert "ACTIONS_RUNTIME_TOKEN GH_TOKEN GITHUB_TOKEN" in measure_step
     assert "secrets." not in measure_step
-    assert "COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/pr-head" in workflow
+    assert (
+        "COVERAGE_SOURCE_WORKDIR: ${{ runner.temp }}/opencode-coverage-"
+        "${{ github.run_id }}-${{ github.run_attempt }}" in workflow
+    )
+    prepare = workflow.split("      - name: Prepare pull request merge tree for coverage measurement", 1)[1].split("      - name:", 1)[0]
+    assert 'mkdir "$COVERAGE_SOURCE_WORKDIR"' in prepare
+    assert 'rm -rf "$COVERAGE_SOURCE_WORKDIR"' not in prepare
     assert (
         'python3 -I - "$COVERAGE_SOURCE_ARCHIVE" "$COVERAGE_SOURCE_WORKDIR"' in workflow
     )

tests/test_pr_review_autofix_nvidia_nim_contract.py

@@ -17,7 +17,7 @@
 DOCTORING_RECORD = Path("docs/doctoring/hourly-nvidia-nim-autofix.md")
 CHANGELOG = Path("CHANGELOG.md")
 REVIEW_DISPATCH_WORKFLOW = Path(".github/workflows/opencode-review-dispatch.yml")
-REVIEW_DISPATCH_BLOB_SHA = "a74d6eaf1a6c998b59d7db152cbb173bdfba7bf8"
+REVIEW_DISPATCH_BLOB_SHA = "0ac2ec1fd69e60b228ac30b0b797403988d1a7ce"
 
 
 def _workflow_text(path: Path) -> str: