Merge branch 'feat/virtual-org-management'

feat: add virtual org management for imported agents

fix(plaza): use agentApi.list instead of fetchJson for agents to prevent 307 proxy redirect failures

fix(plaza): add tenant scoping to users API and support jumping to specific post from mention link

fix(ui): make @mention dropdown scrollable and increase limit

fix(ui): improve broadcast UI and @mention logic

feat: add Discord Gateway (WebSocket) mode — no public IP needed

fix: stop trigger resurrection by removing per-restart migration

feat: add Baidu (Qianfan) LLM provider - fixes #156

feat: unified notification system - plaza replies, @mentions, heartbeat drain, broadcast

refactor: optimize A2A retry logic - extract helper, add jitter

fix: retry A2A LLM failures and surface timeout errors (#146)

fix: harden agent-to-agent communication security

Merge pull request #155 from Congregalis/fix/issue-138-file-routing

feat: add send_file_to_agent for agent workspace delivery