feat: add fallback routes and repository event enrichment

src/types.ts

@@ -43,6 +43,12 @@ export interface Route {
   };
   lang?: string;
   groupId?: string;
+  /**
+   * Fallback route: only fires when no other (non-fallback) route matched the
+   * event. Multiple fallback routes may exist; they are all skipped whenever at
+   * least one regular route matches.
+   */
+  fallback?: boolean;
 }
 
 export interface Group {