feat: add Google code retrieval across desktop CLI and MCP

apps/desktop/src/search-state.ts

@@ -1,3 +1,16 @@
+/** Scope is captured with filters; changing controls cannot mutate active work. */
+export type SearchFilters = Readonly<
+  Record<string, string | number | boolean | null>
+>;
+export function scopedFilters(
+  scope: string,
+  filters: Record<string, string | number | boolean | null>,
+): SearchFilters {
+  if (scope !== "all" && scope !== "code")
+    throw new Error("Choose a valid search scope.");
+  return Object.freeze({ ...filters, code_only: scope === "code" });
+}
+
 /** Let rapid typing settle before starting the model lane. */
 export const SEMANTIC_SETTLE_MS = 120;