fix(docs): align site with bilingual source pairs

docs/user/index.md

@@ -0,0 +1,25 @@
+---
+layout: home
+hero:
+  name: DeepSeek Harness
+  text: Plugin-based agent development framework
+  tagline: Built on the Cordis microkernel; everything is a plugin
+  actions:
+    - theme: brand
+      text: Quick start
+      link: /en/guide/quickstart
+    - theme: alt
+      text: Develop plugins
+      link: /en/develop/basic/
+features:
+  - title: Plugin architecture
+    details: Built on the Cordis plugin system. Every capability is registered by a plugin, takes effect when loaded, and is reverted when unloaded.
+  - title: Configuration as composition
+    details: One cordis.yml determines the agent's complete capability set. Change a model or add a tool by editing configuration.
+  - title: Ready to use
+    details: Includes LLM calls, file access, Bash execution, subagent delegation, and the rest of the core toolchain. Copy a template to get started.
+---
+
+# DeepSeek Harness
+
+English | [中文](index.zh.md)