fix: align reusable review skill staging

.github/workflows/pr-review-reusable.yml

@@ -53,15 +53,17 @@ jobs:
           ref: ${{ inputs.harness-ref }}
           path: harness
           persist-credentials: false
+      - name: Install default review skill
+        run: install -D -m 0644 harness/examples/github-pr-reviewer/skills/pr-review/SKILL.md harness/skills/pr-review/SKILL.md
       - name: Install caller skill
         if: inputs.skill-path != ''
         env:
           SKILL_PATH: ${{ inputs.skill-path }}
         run: |
           [[ "$SKILL_PATH" != /* && "$SKILL_PATH" != *..* ]] || exit 1
           test -f "caller/$SKILL_PATH"
-          install -D -m 0644 "caller/$SKILL_PATH" harness/examples/github-pr-reviewer/skills/pr-review/SKILL.md
-          cmp -s "caller/$SKILL_PATH" harness/examples/github-pr-reviewer/skills/pr-review/SKILL.md
+          install -D -m 0644 "caller/$SKILL_PATH" harness/skills/pr-review/SKILL.md
+          cmp -s "caller/$SKILL_PATH" harness/skills/pr-review/SKILL.md
       - uses: actions/setup-go@v7
         with:
           go-version-file: harness/go.mod
@@ -102,6 +104,7 @@ jobs:
           REVIEW_HEAD: ${{ github.event.pull_request.head.sha }}
           VERTEX_AI_PROJECT_ID: ${{ vars.VERTEX_AI_PROJECT_ID }}
           VERTEX_AI_REGION: ${{ vars.VERTEX_AI_REGION }}
+          REVIEW_SKILL: ${{ github.workspace }}/harness/skills/pr-review/SKILL.md
         run: |
           token="$(gcloud auth print-access-token)"
           echo "::add-mask::$token"

cmd/workflow_apply_test.go

@@ -647,6 +647,68 @@ func TestCanonicalRunRequestResolvesConfigRelativeArtifacts(t *testing.T) {
 	}
 }
 
+func TestGitHubReviewerCustomSkillUsesExamplePayloadPath(t *testing.T) {
+	dir := t.TempDir()
+	exampleDir := filepath.Join("..", "examples", "github-pr-reviewer")
+	workflowPath := filepath.Join(dir, "opencode-harness.yaml")
+	workflowBytes, err := os.ReadFile(filepath.Join(exampleDir, "opencode-harness.yaml"))
+	if err != nil {
+		t.Fatalf("read reviewer workflow: %v", err)
+	}
+	if err := os.WriteFile(workflowPath, workflowBytes, 0o600); err != nil {
+		t.Fatalf("write reviewer workflow: %v", err)
+	}
+	configBytes, err := os.ReadFile(filepath.Join(exampleDir, "opencode-review.json"))
+	if err != nil {
+		t.Fatalf("read reviewer agent config: %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "opencode-review.json"), configBytes, 0o600); err != nil {
+		t.Fatalf("write reviewer agent config: %v", err)
+	}
+	skillPath := filepath.Join(dir, "skills", "pr-review", "SKILL.md")
+	marker := "custom-skill-marker\n"
+	if err := os.MkdirAll(filepath.Dir(skillPath), 0o700); err != nil {
+		t.Fatalf("create skill directory: %v", err)
+	}
+	writeTestFile(t, skillPath, marker)
+
+	diffPath := filepath.Join(dir, "pr.diff")
+	policyPath := filepath.Join(dir, "review-policy.yaml")
+	writeTestFile(t, diffPath, "diff --git a/file b/file\n")
+	writeTestFile(t, policyPath, "version: 1\n")
+	t.Setenv("REVIEW_DIFF", diffPath)
+	t.Setenv("REVIEW_POLICY", policyPath)
+	t.Setenv("REVIEW_REPOSITORY", "owner/repo")
+	t.Setenv("REVIEW_PR", "1")
+	t.Setenv("REVIEW_HEAD", "head")
+	t.Setenv("REVIEW_SKILL", skillPath)
+
+	workflow, err := loadWorkflow(workflowPath, "", "", applyOverrides{})
+	if err != nil {
+		t.Fatalf("loadWorkflow: %v", err)
+	}
+	req, cleanup, err := buildRunRequest(workflow)
+	if err != nil {
+		t.Fatalf("buildRunRequest: %v", err)
+	}
+	defer cleanup()
+
+	for _, upload := range req.Uploads {
+		if upload.Dst != "/sandbox/review/skills/pr-review/SKILL.md" {
+			continue
+		}
+		got, err := os.ReadFile(upload.Src)
+		if err != nil {
+			t.Fatalf("read uploaded skill source: %v", err)
+		}
+		if string(got) != marker {
+			t.Fatalf("uploaded skill = %q, want marker %q", got, marker)
+		}
+		return
+	}
+	t.Fatal("review skill payload was not declared by the example")
+}
+
 func writeTestFile(t *testing.T, path, content string) {
 	t.Helper()
 	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {

examples/github-pr-reviewer/opencode-harness.yaml

@@ -18,7 +18,7 @@ sandbox:
 payloads:
   - source: ${REVIEW_DIFF}
     destination: /sandbox/review/pr.diff
-  - source: skills/pr-review/SKILL.md
+  - source: ${REVIEW_SKILL}
     destination: /sandbox/review/skills/pr-review/SKILL.md
   - source: opencode-review.json
     destination: /sandbox/opencode-review.json

scripts/pr-review.sh

@@ -129,6 +129,7 @@ run_review() {
 
   export REVIEW_DIFF="$REVIEW_DIR/pr.diff"
   export REVIEW_POLICY="$REVIEW_DIR/review-policy.yaml"
+  export REVIEW_SKILL="${REVIEW_SKILL:-examples/github-pr-reviewer/skills/pr-review/SKILL.md}"
   policy_template="${REVIEW_POLICY_TEMPLATE:-examples/github-pr-reviewer/review-policy.yaml}"
   sed \
     -e "s|\${REVIEW_REPOSITORY}|$REVIEW_REPOSITORY|g" \