refactor(agent): remove legacy image mode prompt injection

webui/src/lib/nanobot-client.ts

@@ -3,7 +3,6 @@ import type {
   InboundEvent,
   Outbound,
   OutboundCliAppMention,
-  OutboundImageGeneration,
   OutboundMcpPresetMention,
   OutboundMedia,
   GoalStateWsPayload,
@@ -385,7 +384,6 @@ export class NanobotClient {
     content: string,
     media?: OutboundMedia[],
     options?: {
-      imageGeneration?: OutboundImageGeneration;
       cliApps?: OutboundCliAppMention[];
       mcpPresets?: OutboundMcpPresetMention[];
       workspaceScope?: WorkspaceScopePayload | null;
@@ -398,7 +396,6 @@ export class NanobotClient {
       chat_id: chatId,
       content,
       ...(media && media.length > 0 ? { media } : {}),
-      ...(options?.imageGeneration ? { image_generation: options.imageGeneration } : {}),
       ...(options?.cliApps?.length ? { cli_apps: options.cliApps } : {}),
       ...(options?.mcpPresets?.length ? { mcp_presets: options.mcpPresets } : {}),
       ...(options?.workspaceScope ? { workspace_scope: options.workspaceScope } : {}),