fix(#297): add schema constraint rejecting approve with protected-path findings

schemas/review-result.schema.json

@@ -48,6 +48,25 @@
     {
       "if": { "properties": { "action": { "const": "failure" } }, "required": ["action"] },
       "then": { "required": ["reason"] }
+    },
+    {
+      "if": {
+        "properties": { "action": { "const": "approve" } },
+        "required": ["action"]
+      },
+      "then": {
+        "not": {
+          "properties": {
+            "findings": {
+              "contains": {
+                "properties": { "category": { "const": "protected-path" } },
+                "required": ["category"]
+              }
+            }
+          },
+          "required": ["findings"]
+        }
+      }
     }
   ],
   "$defs": {

scripts/validate-output-schema-test.sh

@@ -374,6 +374,32 @@ run_test_custom_filename "review-approve-valid" \
   "${REVIEW_SCHEMA}" \
   "true"
 
+# --- review-result.schema.json protected-path constraint ---
+
+run_test_custom_filename "review-approve-with-protected-path-rejected" \
+  '{"action":"approve","pr_number":1,"repo":"org/repo","head_sha":"abc1234","body":"Approved.","findings":[{"severity":"high","category":"protected-path","file":".github/workflows/ci.yml","description":"PR modifies protected path."}]}' \
+  "agent-result.json" \
+  "${REVIEW_SCHEMA}" \
+  "false"
+
+run_test_custom_filename "review-comment-with-protected-path-valid" \
+  '{"action":"comment","pr_number":1,"repo":"org/repo","head_sha":"abc1234","body":"Protected paths detected.","findings":[{"severity":"medium","category":"protected-path","file":"CODEOWNERS","description":"PR modifies protected path."}]}' \
+  "agent-result.json" \
+  "${REVIEW_SCHEMA}" \
+  "true"
+
+run_test_custom_filename "review-request-changes-with-protected-path-valid" \
+  '{"action":"request-changes","pr_number":1,"repo":"org/repo","head_sha":"abc1234","body":"Protected paths.","findings":[{"severity":"high","category":"protected-path","file":"scripts/deploy.sh","description":"PR modifies protected path."}]}' \
+  "agent-result.json" \
+  "${REVIEW_SCHEMA}" \
+  "true"
+
+run_test_custom_filename "review-approve-no-protected-path-valid" \
+  '{"action":"approve","pr_number":1,"repo":"org/repo","head_sha":"abc1234","body":"LGTM.","findings":[{"severity":"low","category":"style","file":"main.go","description":"Minor style nit."}]}' \
+  "agent-result.json" \
+  "${REVIEW_SCHEMA}" \
+  "true"
+
 # --- Summary ---
 
 echo ""

skills/pr-review/SKILL.md

@@ -775,7 +775,12 @@ Protected paths (kept in sync with `post-review.sh`):
 For each file in the PR diff, check whether its path starts with (or
 exactly matches) any entry in the list above.
 
-If **any** protected files are modified:
+If **any** protected files are modified, you MUST emit a structured
+finding with `category: "protected-path"`. This is not optional —
+the `review-result.schema.json` schema rejects `action: "approve"`
+when any finding has `category: "protected-path"`, so omitting the
+finding is the only way an approval can slip through. Always emit
+the finding.
 
 1. **Insufficient context** — the PR has no linked issue, or the PR
    description does not explain why the protected files are being
@@ -791,11 +796,13 @@ If **any** protected files are modified:
    approval is always required for protected-path changes, regardless
    of context.
 
-In either case, the presence of a `protected-path` finding at high or
-medium severity means the outcome MUST NOT be `approve`.
+In either case, the presence of a `protected-path` finding means the
+outcome MUST NOT be `approve`. The schema enforces this — validation
+will reject the result if `action` is `approve` and any finding has
+`category: "protected-path"`.
 
-- For high severity, the finding MUST be `request-changes`
-- For medium severity (with sufficient context), the finding MUST be
+- For high severity, the outcome MUST be `request-changes`
+- For medium severity (with sufficient context), the outcome MUST be
   `comment-only`
 
 The `post-review.sh` script independently downgrades approvals on