Auto-deduplicate agent shortname on join request approval

When approving an agent join request with a shortname already in use,
append a numeric suffix (e.g. "openclaw-2") instead of returning an error.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/services/index.ts

@@ -1,5 +1,5 @@
 export { companyService } from "./companies.js";
-export { agentService } from "./agents.js";
+export { agentService, deduplicateAgentName } from "./agents.js";
 export { assetService } from "./assets.js";
 export { projectService } from "./projects.js";
 export { issueService, type IssueFilters } from "./issues.js";