Revert "feat(topics): compute topic overviews and topic pages on the server"

This reverts commit cc04e0944d.

src/lib/validations/topics.ts

@@ -1,28 +0,0 @@
-/**
- * Request schemas of the topic routes (preview): the topic in the path and
- * the window of a topic page. Shared by the routes and the OpenAPI registry.
- */
-import { z } from "zod/v4";
-
-import {
-  DEFAULT_TOPIC_RANGE,
-  TOPIC_KEYS,
-  TOPIC_RANGES,
-} from "@/lib/topics/registry";
-
-export const topicKeySchema = z
-  .enum(TOPIC_KEYS)
-  .describe("The topic, as its URL slug.");
-
-export const topicPathSchema = z.object({ topic: topicKeySchema });
-
-export const topicDetailQuerySchema = z.object({
-  range: z
-    .enum(TOPIC_RANGES)
-    .default(DEFAULT_TOPIC_RANGE)
-    .describe(
-      "The window the side-by-side series cover. The usual ranges, the trends and the relationships always read at least the trailing 90 days.",
-    ),
-});
-
-export type TopicDetailQuery = z.infer<typeof topicDetailQuerySchema>;