fix(cli): preserve installer fallback chains in generated config (#3144)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/cli/model-fallback-types.ts

@@ -1,3 +1,5 @@
+import type { FallbackModelObject } from "../config/schema/fallback-models"
+
 export interface ProviderAvailability {
 	native: {
 		claude: boolean
@@ -15,11 +17,13 @@ kimiForCoding: boolean
 export interface AgentConfig {
 	model: string
 	variant?: string
+	fallback_models?: FallbackModelObject[]
 }
 
 export interface CategoryConfig {
 	model: string
 	variant?: string
+	fallback_models?: FallbackModelObject[]
 }
 
 export interface GeneratedOmoConfig {