fix(review): expose coverage summary list read-only

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

@@ -1297,6 +1297,7 @@ jobs:
               -type f \
               -not -path '*/node_modules/*' \
               -print >"$summary_list"
+            chmod 0444 "$summary_list"
 
             if [ ! -s "$summary_list" ]; then
               append "### JavaScript/TypeScript coverage threshold"

scripts/ci/test_strix_quick_gate.sh

@@ -1001,6 +1001,7 @@ assert_opencode_review_uses_codegraph_and_gpt5_fallback() {
 	assert_file_contains "$workflow_file" "JavaScript/TypeScript dependencies (npm ci, lifecycle hooks disabled)" "opencode coverage evidence installs npm workspace dependencies without lifecycle hooks before JS coverage"
 	assert_file_contains "$workflow_file" "coverage/coverage-summary.json" "opencode coverage evidence reads JS coverage summaries instead of trusting test exit codes"
 	assert_file_contains "$workflow_file" "coverage/coverage-final.json" "opencode coverage evidence supports Vitest Istanbul final coverage files"
+	assert_file_contains "$workflow_file" 'chmod 0444 "$summary_list"' "opencode coverage makes the root-created summary list readable by the unprivileged sandbox user"
 	assert_file_contains "$workflow_file" "javascript_coverage_gate.py" "opencode coverage evidence delegates changed-source measurement to the tested central gate"
 	assert_file_contains "$workflow_file" '--base-sha "$PR_BASE_SHA"' "opencode changed-source coverage is bound to the pull request base"
 	assert_file_contains "$workflow_file" '--head-sha "$PR_HEAD_SHA"' "opencode changed-source coverage is bound to the current pull request head"

tests/test_opencode_agent_contract.py

@@ -408,7 +408,20 @@ def test_opencode_target_coverage_materializes_only_after_authorized_dispatch():
     assert '--store-dir "$writable_pnpm_store_dir"' in measure_step
     assert "pnpm offline install" in measure_step
     assert "--offline" in measure_step
-    assert 'find "$COVERAGE_SOURCE_WORKDIR"' in measure_step
+    coverage_function_start = measure_step.index(
+        "          check_javascript_coverage_thresholds() {\n"
+    )
+    coverage_function_end = measure_step.index(
+        "\n          }\n", coverage_function_start
+    )
+    coverage_function = measure_step[coverage_function_start:coverage_function_end]
+    summary_find = coverage_function.index('find "$COVERAGE_SOURCE_WORKDIR"')
+    summary_find_complete = coverage_function.index(
+        '-print >"$summary_list"', summary_find
+    )
+    summary_chmod = coverage_function.index('chmod 0444 "$summary_list"')
+    summary_argument = coverage_function.index('--summary-list "$summary_list"')
+    assert summary_find < summary_find_complete < summary_chmod < summary_argument
     assert '--repo-root "$COVERAGE_SOURCE_WORKDIR"' in measure_step
     assert "javascript_coverage_ran_any=1" in measure_step
     assert measure_step.count("check_javascript_coverage_thresholds") == 2