refactor(livechat): replace any types in Livechat store with proper TypeScript interfaces

Problem

The Livechat store state in
packages/livechat/src/store/index.tsx
uses multiple any type annotations in the StoreState definition, which significantly reduces type safety and developer confidence.

Currently, there are 19 any usages affecting core Livechat state such as messages, alerts, agents, queue info, and configuration settings.

This:

• Weakens compile-time guarantees
• Reduces IDE autocompletion and discoverability
• Makes future refactors riskier
• Hides potential bugs until runtime

Affected Fields (examples)

messages: any;
triggers: any[];
resources: any;
fileUpload?: any;
allowSwitchingDepartments?: any;
showConnecting?: any;
limitTextLength?: any;
alerts: any[];
unread: any;
incomingCallAlert: any;
businessUnit: any;
modal?: any;
agent?: any;
lastReadMessageId?: any;
triggerAgent?: any;
queueInfo?: any;

(Full list: 19 fields)

Proposed Solution

• Replace all any annotations in StoreState with proper TypeScript types
• Reuse existing shared types from @rocket.chat/core-typings where applicable (e.g. IMessage, ILivechatTrigger)
• Introduce a dedicated types.ts file for Livechat-specific interfaces (alerts, queue info, config objects)
• Keep changes type-only with no runtime behavior modifications

Benefits

• Stronger type safety across the Livechat package
• Better IDE support and autocompletion
• Earlier detection of state-related bugs at compile time
• Improved maintainability and confidence for future contributors

Scope

• Files affected:
  packages/livechat/src/store/index.tsx
packages/livechat/src/store/types.ts (new)
• Runtime behavior: unchanged
• Breaking changes: none

I’m working on this refactor and will open a pull request shortly.

Start with StoreState in packages/livechat/src/store/index.tsx and review the existing shared types mentioned from @rocket.chat/core-typings. Define Livechat-specific interfaces in packages/livechat/src/store/types.ts for the remaining state fields, then replace all 19 any annotations while keeping the changes type-only and runtime behavior unchanged.