fix(social): robot blocks

Blocking an auto-match opponent who is secretly a pooled robot is recorded  instead in a separate `robot_blocks` table.

Now blocking behaves the same in that game (struck name, hidden composer) and lists the blocked opponent under the name you saw, but is recorded only against that game — the disguise holds, the shared robot is never globally blocked, and the matchmaker keeps pairing you with robots (so you can never block yourself out of opponents).

- the shared robot account is never put in `blocks`
- the matchmaker keeps it free and it is not blocked under its other per-game names
- the blocked list and the in-game card still show it by joining that table; an unblock deletes the row

ui/src/lib/mock/client.ts

@@ -13,6 +13,7 @@ import type {
 import { GatewayError } from '../client';
 import type {
   AccountRef,
+  BlockList,
   BlockStatus,
   ChatMessage,
   EvalResult,
@@ -555,10 +556,13 @@ export class MockGateway implements GatewayClient {
   }
 
   // --- blocks ---
-  async blocksList(): Promise<AccountRef[]> {
-    return this.blocks.map((b) => ({ ...b }));
+  async blocksList(): Promise<BlockList> {
+    // The mock models human blocks only (no disguised robots); robots stays empty.
+    return { blocked: this.blocks.map((b) => ({ ...b })), robots: [] };
   }
-  async block(accountId: string): Promise<void> {
+  async block(accountId: string, _gameId?: string): Promise<void> {
+    // A block hides the blocked person from the blocker's own friends list (the real
+    // ListFriends filters them out), without deleting the underlying friendship.
     this.friends = this.friends.filter((f) => f.accountId !== accountId);
     if (!this.blocks.some((b) => b.accountId === accountId)) {
       this.blocks.push({ accountId, displayName: this.nameFor(accountId) });