Merge branch 'pr-1959' into dev

# Conflicts:
#	src/hooks/index.ts
#	src/plugin/event.ts
#	src/tools/delegate-task/sync-task.ts

src/agents/types.ts

@@ -100,6 +100,7 @@ export type AgentName = BuiltinAgentName
 export type AgentOverrideConfig = Partial<AgentConfig> & {
   prompt_append?: string
   variant?: string
+  fallback_models?: string | string[]
 }
 
 export type AgentOverrides = Partial<Record<OverridableAgentName, AgentOverrideConfig>>

src/agents/utils.test.ts

@@ -51,7 +51,7 @@ describe("createBuiltinAgents with model overrides", () => {
     expect(agents.sisyphus.thinking).toBeUndefined()
   })
 
-  test("Atlas uses uiSelectedModel when provided", async () => {
+  test("Atlas uses uiSelectedModel", async () => {
     // #given
     const fetchSpy = spyOn(shared, "fetchAvailableModels").mockResolvedValue(
       new Set(["openai/gpt-5.2", "anthropic/claude-sonnet-4-6"])