Add system architecture diagrams to README files

Introduced detailed system architecture and request processing flow diagrams using Mermaid in the English, Simplified Chinese, and Traditional Chinese README files. These additions provide a clearer overview of the platform's internal structure and request handling logic for developers and users.

README.md

@@ -138,6 +138,83 @@ In-depth technical analysis article published: ***[Deep Dive into Xget: A High-P
 - **Download Tool Compatibility**: Perfect support for wget, cURL, aria2, IDM, and other mainstream download tools
 - **CI/CD Integration**: Can be used directly in GitHub Actions, GitLab CI, and other environments
 
+## 🏗️ System Architecture
+
+### Request Processing Flow
+
+```mermaid
+graph TD
+    Request[User Request / User-Agent] --> Identify{Identify Platform}
+    Identify -->|Invalid| Error[Return Error]
+    Identify -->|Valid| Transform[Transform Path]
+    
+    Transform --> CheckProtocol{Check Protocol}
+    
+    CheckProtocol -->|Git| GitHandler[Git Protocol Adapter]
+    CheckProtocol -->|Docker| DockerHandler[Docker Protocol Adapter]
+    CheckProtocol -->|AI| AIHandler[AI Inference Adapter]
+    CheckProtocol -->|Standard| StdHandler[Standard Adapter]
+    
+    GitHandler --> Upstream[Fetch Upstream]
+    DockerHandler --> Upstream
+    AIHandler --> Upstream
+    
+    StdHandler --> CacheCheck{Check Cache}
+    CacheCheck -->|Hit| ReturnCache[Return Cached Response]
+    CacheCheck -->|Miss| Upstream
+    
+    Upstream -->|Success| ProcessResponse[Process Response]
+    Upstream -->|Failure| Retry{Retry?}
+    
+    Retry -->|Yes| Wait[Wait (Backoff)] --> Upstream
+    Retry -->|No| Error
+    
+    ProcessResponse --> Finalize[Add Headers & Return]
+    Finalize --> Response[Response]
+```
+
+### Component Architecture
+
+```mermaid
+classDiagram
+    class Worker {
+        +handleRequest(request)
+    }
+    class Config {
+        +PLATFORMS
+        +transformPath()
+    }
+    class Validation {
+        +validateRequest()
+        +isDockerRequest()
+    }
+    class GitProtocol {
+        +configureGitHeaders()
+        +isGitRequest()
+    }
+    class DockerProtocol {
+        +handleDockerAuth()
+        +fetchToken()
+    }
+    class AIProtocol {
+        +configureAIHeaders()
+    }
+    class Security {
+        +addSecurityHeaders()
+    }
+    class Performance {
+        +monitor()
+    }
+
+    Worker --> Config
+    Worker --> Validation
+    Worker --> GitProtocol
+    Worker --> DockerProtocol
+    Worker --> AIProtocol
+    Worker --> Security
+    Worker --> Performance
+```
+
 ## 📖 URL Conversion Rules
 
 Using the pre-deployed instance **`xget.xi-xu.me`** or your own deployed instance, simply replace the domain and add the platform prefix: