refactor: drop mode from frontend types; react to settings changes

src/types.ts

@@ -22,10 +22,7 @@ export interface CellContext {
   error: ErrorOutput | null;
 }
 
-export type OpenCodeMode = 'optimize' | 'fix' | 'edit';
-
 export interface OpenCodeRequest {
-  mode: OpenCodeMode;
   prompt: string;
   context: CellContext;
   providerId?: string;
@@ -34,7 +31,6 @@ export interface OpenCodeRequest {
 
 export interface OpenCodeSuccess {
   ok: true;
-  mode: OpenCodeMode;
   finalSource: string;
   sessionId: string;
   notebookPath: string;