refactor!: migrate from REST API to GraphQL

- Replace OpenAPI/REST endpoints with a single  route.
- Remove  and Swagger UI configuration.
- Disable OpenAPI schema extensions in Zod types.
- Refactor  to be request-agnostic.
- Update episode URL fetching to return standardized success/failure objects.
- Update project dependencies.

vitest.config.ts

@@ -0,0 +1,24 @@
+import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
+
+export default defineWorkersConfig({
+  test: {
+    globals: true,
+    setupFiles: ["./testSetup.ts"],
+    poolOptions: {
+      workers: {
+        wrangler: { configPath: "./wrangler.toml" },
+      },
+    },
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "json", "html"],
+      exclude: [
+        "node_modules/**",
+        "dist/**",
+        "**/*.spec.ts",
+        "**/*.d.ts",
+        "**/mocks/**",
+      ],
+    },
+  },
+});