Add initial VibeGuard browser extension

src/inference/cache.ts

@@ -0,0 +1,22 @@
+import { hashText, normalizeText } from "../shared/hash";
+import type { InferenceResult } from "../shared/types";
+
+export class ResultCache {
+  private readonly values = new Map<string, InferenceResult>();
+
+  get(text: string): InferenceResult | undefined {
+    return this.values.get(hashText(text));
+  }
+
+  set(text: string, result: InferenceResult): void {
+    this.values.set(hashText(normalizeText(text)), result);
+  }
+
+  clear(): void {
+    this.values.clear();
+  }
+
+  get size(): number {
+    return this.values.size;
+  }
+}