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/util/tool-display.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, test } from "bun:test"
+import { toolDisplayMetadata, webSearchProviderLabel } from "../../src/util/tool-display"
+
+describe("webSearchProviderLabel", () => {
+  test("labels known providers", () => {
+    expect(webSearchProviderLabel("parallel")).toBe("Parallel Web Search")
+    expect(webSearchProviderLabel("exa")).toBe("Exa Web Search")
+  })
+
+  for (const [name, provider] of [
+    ["undefined", undefined],
+    ["null", null],
+    ["an object", {}],
+    ["an array", []],
+    ["a number", 1],
+    ["an unexpected string", "other"],
+  ] as const) {
+    test(`uses the generic label for ${name}`, () => {
+      expect(webSearchProviderLabel(provider)).toBe("Web Search")
+    })
+  }
+})
+
+describe("toolDisplayMetadata", () => {
+  test("returns structured metadata for non-pending states", () => {
+    const structured = { provider: "parallel", numResults: 3 }
+
+    expect(toolDisplayMetadata({ status: "running", structured })).toBe(structured)
+    expect(toolDisplayMetadata({ status: "completed", structured })).toBe(structured)
+    expect(toolDisplayMetadata({ status: "error", structured })).toBe(structured)
+  })
+
+  test("does not expose pending or malformed metadata", () => {
+    expect(toolDisplayMetadata({ status: "pending", structured: { provider: "exa" } })).toEqual({})
+    expect(toolDisplayMetadata({ status: "completed" })).toEqual({})
+    expect(toolDisplayMetadata({ status: "completed", structured: null })).toEqual({})
+    expect(toolDisplayMetadata({ status: "completed", structured: [] })).toEqual({})
+    expect(toolDisplayMetadata(undefined)).toEqual({})
+  })
+})