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/opencode/test/fixture/config.ts

@@ -0,0 +1,23 @@
+import { Config } from "@/config/config"
+import { emptyConsoleState } from "@opencode-ai/core/v1/config/console-state"
+import { Effect, Layer } from "effect"
+
+export function make(overrides: Partial<Config.Interface> = {}) {
+  return Config.Service.of({
+    get: () => Effect.succeed({}),
+    getGlobal: () => Effect.succeed({}),
+    getConsoleState: () => Effect.succeed(emptyConsoleState),
+    update: () => Effect.void,
+    updateGlobal: (config) => Effect.succeed({ info: config, changed: false }),
+    invalidate: () => Effect.void,
+    directories: () => Effect.succeed([]),
+    waitForDependencies: () => Effect.void,
+    ...overrides,
+  })
+}
+
+export function layer(overrides?: Partial<Config.Interface>) {
+  return Layer.succeed(Config.Service, make(overrides))
+}
+
+export * as TestConfig from "./config"