refactor(api): ♻️ Move all client schema code to new package

packages/client/schemas/marker.ts

@@ -0,0 +1,26 @@
+import { z } from "@hono/zod-openapi";
+import { Id } from "./common.ts";
+
+export const Marker = z
+    .object({
+        last_read_id: Id.openapi({
+            description: "The ID of the most recently viewed entity.",
+            example: "ead15c9d-8eda-4b2c-9546-ecbf851f001c",
+        }),
+        version: z.number().openapi({
+            description:
+                "An incrementing counter, used for locking to prevent write conflicts.",
+            example: 462,
+        }),
+        updated_at: z.string().datetime().openapi({
+            description: "The timestamp of when the marker was set.",
+            example: "2025-01-12T13:11:00Z",
+        }),
+    })
+    .openapi({
+        description:
+            "Represents the last read position within a user's timelines.",
+        externalDocs: {
+            url: "https://docs.joinmastodon.org/entities/Marker",
+        },
+    });