feat: Implement agent availability status with a toggle for agents and display on user profiles.

src/services/agents.service.ts

@@ -28,6 +28,7 @@ export interface AgentProfile {
   isVerified: boolean;
   isFeatured: boolean;
   isActive: boolean;
+  isAvailable: boolean;
   agentTypeId: string | null;
   agentType: AgentType | null;
   user?: {
@@ -121,6 +122,7 @@ export interface PublicAgentProfile {
   reviewCount: number;
   isVerified: boolean;
   isFeatured: boolean;
+  isAvailable: boolean;
   agentTypeId: string | null;
   agentType: AgentType | null;
   createdAt?: string;