feat: add route debug logger

Author: tharropoulos

src/analysis/debug.ts

@@ -0,0 +1,18 @@
+import type { DebugConfig } from "../types.js";
+
+export function createDebugLogger(
+  routeKey: string,
+  debugConfig: DebugConfig,
+): (message: string) => void {
+  const filter = debugConfig.routeFilter;
+  const enabled = debugConfig.enabled || filter !== undefined;
+  const shouldLog = filter === undefined || routeKey.includes(filter);
+
+  if (!enabled || !shouldLog) {
+    return () => {};
+  }
+
+  return (message: string): void => {
+    process.stderr.write(`[extractor:${routeKey}] ${message}\n`);
+  };
+}