fix(ui): resolve control chat avatar fallback

ui/src/ui/views/chat.test.ts

@@ -1,3 +1,5 @@
+/* @vitest-environment jsdom */
+
 import { render } from "lit";
 import { describe, expect, it, vi } from "vitest";
 import type { SessionsListResult } from "../types.ts";
@@ -54,6 +56,46 @@ function createProps(overrides: Partial<ChatProps> = {}): ChatProps {
 }
 
 describe("chat view", () => {
+  it("uses the assistant avatar URL for the welcome state when the identity avatar is only initials", () => {
+    const container = document.createElement("div");
+    render(
+      renderChat(
+        createProps({
+          assistantName: "Assistant",
+          assistantAvatar: "A",
+          assistantAvatarUrl: "/avatar/main",
+        }),
+      ),
+      container,
+    );
+
+    const welcomeImage = container.querySelector<HTMLImageElement>(".agent-chat__welcome > img");
+    expect(welcomeImage).not.toBeNull();
+    expect(welcomeImage?.getAttribute("src")).toBe("/avatar/main");
+  });
+
+  it("falls back to the bundled logo in the welcome state when the assistant avatar is not a URL", () => {
+    const container = document.createElement("div");
+    render(
+      renderChat(
+        createProps({
+          assistantName: "Assistant",
+          assistantAvatar: "A",
+          assistantAvatarUrl: null,
+        }),
+      ),
+      container,
+    );
+
+    const welcomeImage = container.querySelector<HTMLImageElement>(".agent-chat__welcome > img");
+    const logoImage = container.querySelector<HTMLImageElement>(
+      ".agent-chat__welcome .agent-chat__avatar--logo img",
+    );
+    expect(welcomeImage).toBeNull();
+    expect(logoImage).not.toBeNull();
+    expect(logoImage?.getAttribute("src")).toBe("favicon.svg");
+  });
+
   it("renders compacting indicator as a badge", () => {
     const container = document.createElement("div");
     render(

ui/src/ui/views/chat.ts

@@ -31,7 +31,7 @@ import { detectTextDirection } from "../text-direction.ts";
 import type { GatewaySessionRow, SessionsListResult } from "../types.ts";
 import type { ChatItem, MessageGroup } from "../types/chat-types.ts";
 import type { ChatAttachment, ChatQueueItem } from "../ui-types.ts";
-import { agentLogoUrl } from "./agents-utils.ts";
+import { agentLogoUrl, resolveAgentAvatarUrl } from "./agents-utils.ts";
 import { renderMarkdownSidebar } from "./markdown-sidebar.ts";
 import "../components/resizable-divider.ts";
 
@@ -566,7 +566,12 @@ const WELCOME_SUGGESTIONS = [
 
 function renderWelcomeState(props: ChatProps): TemplateResult {
   const name = props.assistantName || "Assistant";
-  const avatar = props.assistantAvatar ?? props.assistantAvatarUrl;
+  const avatar = resolveAgentAvatarUrl({
+    identity: {
+      avatar: props.assistantAvatar ?? undefined,
+      avatarUrl: props.assistantAvatarUrl ?? undefined,
+    },
+  });
   const logoUrl = agentLogoUrl(props.basePath ?? "");
 
   return html`
@@ -802,7 +807,13 @@ export function renderChat(props: ChatProps) {
   const showReasoning = props.showThinking && reasoningLevel !== "off";
   const assistantIdentity = {
     name: props.assistantName,
-    avatar: props.assistantAvatar ?? props.assistantAvatarUrl ?? null,
+    avatar:
+      resolveAgentAvatarUrl({
+        identity: {
+          avatar: props.assistantAvatar ?? undefined,
+          avatarUrl: props.assistantAvatarUrl ?? undefined,
+        },
+      }) ?? null,
   };
   const pinned = getPinnedMessages(props.sessionKey);
   const deleted = getDeletedMessages(props.sessionKey);

vitest.config.ts

@@ -83,6 +83,7 @@ export default defineConfig({
       "extensions/**/*.test.ts",
       "test/**/*.test.ts",
       "ui/src/ui/views/agents-utils.test.ts",
+      "ui/src/ui/views/chat.test.ts",
       "ui/src/ui/views/usage-render-details.test.ts",
       "ui/src/ui/controllers/agents.test.ts",
       "ui/src/ui/controllers/chat.test.ts",