docs: release notes for Studio 2.18.0

The first notes written to docs/DOCS_STANDARD.md section 6 and held by
the release-note gate: one summary line, fixed group headings, one
referenced line per user-visible change. repolint -strict reports
nothing for the file.

Left out as not visible to users: the documentation standard,
CODEOWNERS, the repolint rules, the removal of site/ and of the main-v2
release workflows. Also left out: c37dac3a4, which fixed a regression
introduced and fixed between 2.17.0 and this release.

release-notes/studio/2.18.0.md

@@ -0,0 +1,16 @@
+本版修复 Windows 窗口打不开、读图模型误报看不到图、问题框不弹出，并精简内置文档。
+
+## 修复
+
+- Windows 安装目录带 AppContainer 包授权时窗口打不开；启动时自动移除这类授权 #10435
+- 读图模型不再声称看不到已附加的图片 (44150b0aa)
+- Goal 续跑时不再提示读图模型"无法读图" (44150b0aa)
+- 切换模型、重载扩展或切换工作区后，问题框和审批框不再被吞掉 (921a04bda)
+
+## 变更
+
+- 内置文档除 README、使用指南、CLI 参考外只保留英文版，中文提问会检索到英文文档 (68b031ae5)
+
+## 移除
+
+- 内置文档检索中的版本历史，其内容停留在旧产品线的 1.24.1 (99c5360fd)