Livechat triggers: agent sender resolution is globally cached for 1 hour, causing cross-trigger sender leakage

Description:

Livechat trigger agent resolution is cached globally for 1 hour in the widget, causing sender/agent leakage across different trigger configurations.

A trigger action that resolves agent A can affect later trigger actions that should resolve agent B (or queue), because getAgent() reuses a single module-level cached Promise instead of caching by trigger sender context.

Steps to reproduce:

1. Enable Livechat and create two triggers:
   • Trigger 1:
     • Condition: chat-opened-by-visitor
     • Action: send-message
     • Params: sender=custom, name=agent_one, msg=first trigger message
   • Trigger 2:
     • Condition: after-guest-registration
     • Action: send-message
     • Params: sender=custom, name=agent_two, msg=second trigger message
2. Open /livechat as a fresh visitor and open the widget.
3. Confirm Trigger 1 fires and message sender is agent_one.
4. Register/send first visitor message so Trigger 2 fires.
5. Observe Trigger 2 message sender.

Expected behavior:

Each trigger action should resolve sender/agent independently from its own action params.

For the example above, Trigger 2 should use agent_two.

Actual behavior:

Trigger 2 may reuse the cached result from Trigger 1 and still use agent_one (or stale queue result), because sender resolution is globally cached for 1 hour.

Server Setup Information:

• Version of Rocket.Chat Server: develop (observed from current source code path)
• License Type: N/A
• Number of Users: N/A
• Operating System: N/A
• Deployment Method: Local development
• Number of Running Instances: 1
• DB Replicaset Oplog: N/A
• NodeJS Version: N/A
• MongoDB Version: N/A

Client Setup Information

• Desktop App or Browser Version: Browser (Livechat widget)
• Operating System: Any

Additional context

Relevant code paths:

• packages/livechat/src/lib/triggerUtils.ts
  • Global cache: let agentPromise ...
  • TTL: agentCacheExpiry = 3600000
  • getAgent() returns the same cached promise for all actions during TTL.
• packages/livechat/src/lib/triggers.js
  • Multiple triggers share execution path: processTriggers -> schedule -> fire.
• packages/livechat/src/lib/triggerActions.ts
  • Both send-message and use-external-service actions call getAgent().

This creates cross-trigger contamination and stale sender behavior.

Relevant logs:

No server error is required to reproduce.
Behavior is visible in widget trigger messages (sender mismatch with configured trigger action params).

Start in packages/livechat/src/lib/triggerUtils.ts by inspecting the module-level agentPromise, its one-hour expiry, and getAgent(). Then trace the calls from packages/livechat/src/lib/triggerActions.ts through packages/livechat/src/lib/triggers.js; done means separate trigger actions resolve their configured senders independently without reusing another trigger's agent or queue result.