Reject embedded reserved summary markers

Co-authored-by: c1-squire-dev[bot] <c1-squire-dev[bot]@users.noreply.github.com>

Author: gontzess

.github/actions/pr-review/action.yml

@@ -68,8 +68,8 @@ runs:
           exit 1
         fi
         for reserved in "### Connector PR Review:" "### General PR Review:" "### PR Review:"; do
-          if [[ "${SUMMARY_MARKER}" != "${reserved}" && "${SUMMARY_MARKER}" == "${reserved}"* ]]; then
-            echo "::error::summary_marker must not extend a reserved review heading"
+          if [[ "${SUMMARY_MARKER}" != "${reserved}" && "${SUMMARY_MARKER}" == *"${reserved}"* ]]; then
+            echo "::error::summary_marker must not embed a reserved review heading"
             exit 1
           fi
         done

.github/actions/pr-review/scripts/fetch-pr-context.py

@@ -50,12 +50,12 @@ def is_valid_summary_heading(value: str) -> bool:
         return False
     if not value.startswith("### ") or not value.endswith(":"):
         return False
-    # Prefix-based legacy consumers must not mistake a custom summary for
+    # Substring-based legacy consumers must not mistake a custom summary for
     # their own. Exact built-in headings remain valid for existing callers.
-    if value != LEGACY_REVIEW_SUMMARY_HEADING and value.startswith(LEGACY_REVIEW_SUMMARY_HEADING):
+    if value != LEGACY_REVIEW_SUMMARY_HEADING and LEGACY_REVIEW_SUMMARY_HEADING in value:
         return False
     for reserved in BUILT_IN_REVIEW_SUMMARY_HEADINGS:
-        if value != reserved and value.startswith(reserved):
+        if value != reserved and reserved in value:
             return False
     return bool(value[len("### "):-1].strip())
 

.github/actions/pr-review/scripts/test_verdict_scaffolding.py

@@ -628,11 +628,14 @@ def test_rejects_malformed_headings(self):
             with self.subTest(value=value):
                 self.assertFalse(fpc.is_valid_summary_heading(value))
 
-    def test_rejects_reserved_heading_extensions(self):
+    def test_rejects_reserved_heading_collisions(self):
         for value in (
             "### Connector PR Review: Replay:",
             "### General PR Review: Replay:",
             "### PR Review: Replay:",
+            "### Replay: ### Connector PR Review:",
+            "### Replay: ### General PR Review:",
+            "### Replay: ### PR Review:",
         ):
             with self.subTest(value=value):
                 self.assertFalse(fpc.is_valid_summary_heading(value))