fix: 修正 logo 中 N 和 G 字母造型

N 添加对角线笔画（█▄ █），G 添加内横杠（█ ▀█），
避免与 O 字母造型雷同。同步更新 ui.ts 中的硬编码 wordmark。

packages/storybook/.storybook/mocks/app/context/sdk.ts

@@ -0,0 +1,25 @@
+const make = (directory: string) => ({
+  session: {
+    create: async () => ({ data: { id: "story-session" } }),
+    prompt: async () => ({ data: undefined }),
+    shell: async () => ({ data: undefined }),
+    command: async () => ({ data: undefined }),
+    abort: async () => ({ data: undefined }),
+  },
+  worktree: {
+    create: async () => ({ data: { directory: `${directory}/worktree-1` } }),
+  },
+})
+
+const root = "/tmp/story"
+
+export function useSDK() {
+  return {
+    directory: root,
+    url: "http://localhost:4096",
+    client: make(root),
+    createClient(input: { directory: string }) {
+      return make(input.directory)
+    },
+  }
+}