refactor: enhance preflightPayload type definition for clarity

Updated the type definition of preflightPayload in index.ts to improve readability and maintainability. The new structure explicitly outlines the possible types, ensuring better understanding of the variable's usage in the context of preflight handling.

Author: PatrickSys

src/index.ts

@@ -1192,7 +1192,10 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
 
         // For edit/refactor/migrate: return full preflight card (risk, patterns, impact, etc.).
         // For explore or lite-only: return flattened { ready, reason }.
-        let preflightPayload: { ready: boolean; reason?: string } | Record<string, unknown> | undefined;
+        let preflightPayload:
+          | { ready: boolean; reason?: string }
+          | Record<string, unknown>
+          | undefined;
         if (preflight) {
           const el = preflight.evidenceLock;
           // Full card per tool schema; add top-level ready/reason for backward compatibility