feat(agent): make model presets session-scoped (#4866)

webui/src/lib/api.ts

@@ -132,6 +132,7 @@ export async function listSessions(
     updated_at: string | null;
     title?: string;
     preview?: string;
+    model_preset?: string | null;
     run_started_at?: number | null;
     workspace_scope?: WorkspaceScopePayload | null;
   };
@@ -148,6 +149,7 @@ export async function listSessions(
     updatedAt: s.updated_at,
     title: s.title ?? "",
     preview: s.preview ?? "",
+    modelPreset: s.model_preset ?? null,
     runStartedAt: s.run_started_at ?? null,
     workspaceScope: s.workspace_scope ?? null,
   }));

webui/src/lib/types.ts

@@ -245,6 +245,8 @@ export interface ChatSummary {
   updatedAt: string | null;
   title?: string;
   preview: string;
+  /** Model preset persisted for this session; null means it still follows the global default. */
+  modelPreset?: string | null;
   /** Unix epoch seconds when this session currently has a turn in flight. */
   runStartedAt?: number | null;
   workspaceScope?: WorkspaceScopePayload | null;
@@ -406,6 +408,7 @@ export interface SettingsPayload {
     is_default: boolean;
     model: string;
     provider: string;
+    resolved_provider?: string | null;
     max_tokens: number;
     context_window_tokens: number;
     temperature: number;