feat: enhance condition node functionality with branches and validation

- Introduced WorkflowConditionBranch and WorkflowNodeConfig types to manage condition branches in nodes.
- Updated NodeConfigPanel and ConditionNodePanel components to support adding, editing, and deleting branches.
- Implemented validation for condition nodes to ensure at least one branch exists and that default branches are correctly configured.
- Modified workflow-utils to handle condition branches and updated toApiDefinition and fromApiDefinition functions to maintain branch integrity during serialization.
- Removed edge condition handling from WorkflowEditor and related components, simplifying edge management.
- Added tests to ensure condition branches are preserved in API definitions.

web/lib/api/admin.ts

@@ -318,18 +318,12 @@ export type AIWorkflowDefinition = {
     config: Record<string, unknown>
     inputs?: Record<string, AIWorkflowVariableSelector>
   }[]
-  edges: {
-    id: string
-    source: string
-    target: string
-    condition?: {
-      expression?: string
-      left?: AIWorkflowVariableSelector
-      operator?: string
-      right?: unknown
-    }
-  }[]
-}
+	  edges: {
+	    id: string
+	    source: string
+	    target: string
+	  }[]
+	}
 
 export type AIWorkflow = {
   id: number