fix(social): allow single-char search and prefer native federated profiles

Lower minimum query length from 2 to 1 character so single-letter
searches return results.

Fix dedup to prefer native profiles (homeUserId=null) over replicated
ones. Previously the first-seen result won, which was usually the
local replicated profile (no instance badge, namespaced username).
Now when a native profile is found on the remote instance, it replaces
the replicated copy — showing the clean username with the instance badge.

packages/server/src/routes/social.ts

@@ -483,7 +483,7 @@ export async function socialRoutes(app: FastifyInstance): Promise<void> {
     const { q } = request.query;
     const db = getDb();
 
-    if (!q || q.length < 2) {
+    if (!q || q.length < 1) {
       return reply.code(200).send([]);
     }