feat(FN-5144): add create-pr metadata and preflight routes

Added GitHub create-PR metadata and preflight routes to the dashboard, wiring up `submit-github.pr-options-preflight-metadata` contract and integration tests for the new preflight/confirm flow alongside supporting test configuration updates.

Fusion-Task-Id: FN-5144

scripts/test-changed.mjs

@@ -323,6 +323,23 @@ export function expandWithReverseDependents(packageNames, reverseDependencyMap)
   return [...expanded];
 }
 
+// FN-5154 / FN-5157: root docs, changeset summaries, and .fusion artifacts should not expand changed-only test runs into a full workspace suite.
+function isTestIrrelevantRootPath(file) {
+  if (file.startsWith(".fusion/")) {
+    return true;
+  }
+
+  if (/^\.changeset\/[^/]+\.md$/.test(file)) {
+    return true;
+  }
+
+  if (!file.includes("/") && file.toLowerCase().endsWith(".md")) {
+    return true;
+  }
+
+  return ["README", "CHANGELOG.md", "LICENSE", "LICENSE.md"].includes(file);
+}
+
 export function shouldForceFullSuite(changedFiles) {
   const fullSuitePaths = [
     "package.json",
@@ -345,6 +362,10 @@ export function shouldForceFullSuite(changedFiles) {
       return true;
     }
 
+    if (isTestIrrelevantRootPath(file)) {
+      return false;
+    }
+
     if ((file.startsWith("packages/") || file.startsWith("plugins/")) && /vitest|test/.test(path.basename(file))) {
       return false;
     }