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/slack/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "@opencode-ai/slack",
+  "version": "1.17.4",
+  "type": "module",
+  "license": "MIT",
+  "scripts": {
+    "dev": "bun run src/index.ts",
+    "typecheck": "tsgo --noEmit"
+  },
+  "dependencies": {
+    "@opencode-ai/sdk": "workspace:*",
+    "@slack/bolt": "^3.17.1"
+  },
+  "devDependencies": {
+    "@types/node": "catalog:",
+    "typescript": "catalog:",
+    "@typescript/native-preview": "catalog:"
+  }
+}