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/tui/test/prompt/persistence.test.ts

@@ -0,0 +1,23 @@
+import { expect, test } from "bun:test"
+import path from "path"
+import { mkdtemp, rm } from "fs/promises"
+import { tmpdir } from "os"
+import { appendText, readJson, readText, writeJsonAtomic, writeText } from "../../src/util/persistence"
+
+test("persistence creates parent directories and supports text, append, and JSON", async () => {
+  const root = await mkdtemp(path.join(tmpdir(), "opencode-tui-persistence-"))
+  try {
+    const textPath = path.join(root, "nested", "state.jsonl")
+    await writeText(textPath, "one\n")
+    await appendText(textPath, "two\n")
+    expect(await readText(textPath)).toBe("one\ntwo\n")
+
+    const jsonPath = path.join(root, "other", "state.json")
+    await writeJsonAtomic(jsonPath, { value: 1 })
+    expect(await readJson<{ value: number }>(jsonPath)).toEqual({ value: 1 })
+    await writeJsonAtomic(jsonPath, { value: 2 })
+    expect(await readJson<{ value: number }>(jsonPath)).toEqual({ value: 2 })
+  } finally {
+    await rm(root, { recursive: true, force: true })
+  }
+})