refactor(ai-chat): 移除 excel_analyze/office_analyze 工具与 OfficeKit 依赖

- 删除 excel_analyze/office_analyze 两个 A2UI 工具（schema、分发、执行器、测试）
- 附件分析改为依赖上传时自动提取的文本与 preflight_import 报告 errorSamples
- 移除 @officecli/officecli 依赖及 OfficeCliService（PPT 上传不再自动提取文本）
- 保留 AiExcelReaderService（附件文本提取与导入预检仍使用）

package-lock.json

@@ -102,7 +102,6 @@
         "@nestjs/schedule": "^6.1.3",
         "@nestjs/throttler": "^6.5.0",
         "@nestjs/typeorm": "^11.0.1",
-        "@officecli/officecli": "^1.0.143",
         "@types/multer": "^2.1.0",
         "bcryptjs": "^3.0.3",
         "class-transformer": "^0.5.1",
@@ -3847,28 +3846,6 @@
         "url": "https://paulmillr.com/funding/"
       }
     },
-    "node_modules/@officecli/officecli": {
-      "version": "1.0.143",
-      "resolved": "https://registry.npmmirror.com/@officecli/officecli/-/officecli-1.0.143.tgz",
-      "integrity": "sha512-6fNynmrNso9wiRf2mIs6magdFHKQbsQC6u5qsZtwWwgZrc/kNr5++Wajp220sBnFPPuRiuKx1xy8LW+I2MZEbw==",
-      "cpu": [
-        "x64",
-        "arm64"
-      ],
-      "hasInstallScript": true,
-      "license": "Apache-2.0",
-      "os": [
-        "darwin",
-        "linux",
-        "win32"
-      ],
-      "bin": {
-        "officecli": "officecli.js"
-      },
-      "engines": {
-        "node": ">=14"
-      }
-    },
     "node_modules/@oxc-project/types": {
       "version": "0.138.0",
       "resolved": "https://registry.npmmirror.com/@oxc-project/types/-/types-0.138.0.tgz",