docs: add OpenSIN-Code documentation - core engine, rust engine, 14 plugins

- docs/guide/opensin-code.md: Complete OpenSIN-Code architecture overview
- docs/guide/opensin-code-rust-engine.md: Rust Engine documentation
- docs/plugins/opensin-code-plugins.md: All 14 migrated plugins documented
- .vitepress/config.js: Navigation entries added

Author: Stealth Crew

.vitepress/config.js

@@ -28,6 +28,8 @@ export default defineConfig({
           { text: 'Scaling', link: '/docs/guide/scaling' },
           { text: 'Troubleshooting', link: '/docs/guide/troubleshooting' },
           { text: 'Changelog', link: '/docs/guide/changelog' },
+          { text: 'OpenSIN Code', link: '/docs/guide/opensin-code' },
+          { text: 'Rust Engine', link: '/docs/guide/opensin-code-rust-engine' },
         ],
       },
       {

docs/guide/opensin-code-rust-engine.md

@@ -0,0 +1,224 @@
+# OpenSIN Code Rust Engine
+
+Die Rust Engine (`opensin-engine`) ist das performante Backend von OpenSIN-Code.
+
+> **Pfad:** `packages/opensin-engine/`
+> **Umfang:** 71 Dateien | 48 Rust-Files | 37.731 Zeilen
+
+---
+
+## Struktur
+
+```
+packages/opensin-engine/
+├── Cargo.toml              # Workspace Definition
+├── Cargo.lock              # Dependency Lockfile
+├── SIN.md                  # OpenSIN Code Dokumentation
+├── PARITY.md               # Feature Parity mit TypeScript
+├── README.md               # Engine Dokumentation
+├── CONTRIBUTING.md         # Contributing Guidelines
+└── crates/
+    ├── api/                # API Layer (7 Dateien)
+    │   └── src/
+    │       ├── lib.rs      # Module Exports
+    │       ├── client.rs   # ProviderClient Abstraction
+    │       ├── types.rs    # StreamEvent, MessageRequest
+    │       ├── error.rs    # ApiError Enum
+    │       ├── sse.rs      # SSE Parser
+    │       └── providers/
+    │           ├── mod.rs          # Provider Trait, Model Registry
+    │           ├── openai_provider.rs  # OpenAI API Client
+    │           └── openai_compat.rs    # OpenAI/xAI via OCI Proxy
+    ├── runtime/            # Runtime Layer (18 Dateien)
+    │   └── src/
+    │       ├── lib.rs          # Module Exports
+    │       ├── conversation.rs # Core Agent Loop
+    │       ├── config.rs       # Multi-source Config Loading
+    │       ├── session.rs      # Session Persistence
+    │       ├── compact.rs      # Session Compaction Algorithm
+    │       ├── bash.rs         # Bash Execution with Sandbox
+    │       ├── file_ops.rs     # Read/Write/Edit/Glob/Grep
+    │       ├── oauth.rs        # OAuth Flow with PKCE
+    │       ├── sandbox.rs      # Linux Namespace Isolation
+    │       ├── hooks.rs        # Pre/Post Tool Hooks
+    │       ├── prompt.rs       # System Prompt Building
+    │       ├── mcp.rs          # MCP Tool Naming
+    │       ├── mcp_client.rs   # Transport Abstraction
+    │       ├── mcp_stdio.rs    # JSON-RPC over stdio
+    │       ├── permissions.rs  # Permission Mode Enforcement
+    │       ├── remote.rs       # Upstream Proxy Support
+    │       ├── usage.rs        # Token Usage Tracking
+    │       ├── sse.rs          # SSE Event Parsing
+    │       ├── bootstrap.rs    # Bootstrap Phases
+    │       └── json.rs         # Custom JSON Parser/Renderer
+    ├── tools/              # Tools Layer (1 Datei, ~2.500 Zeilen)
+    │   └── src/
+    │       └── lib.rs      # 19 Built-in Tools
+    ├── commands/           # Commands Layer (1 Datei, ~1.800 Zeilen)
+    │   └── src/
+    │       └── lib.rs      # 27+ Slash Commands
+    ├── sin-cli/            # CLI Layer (6 Dateien)
+    │   └── src/
+    │       ├── main.rs     # CLI Entry, REPL, OAuth Login
+    │       ├── app.rs      # SessionApp, Slash Command Handling
+    │       ├── args.rs     # Clap Argument Parsing
+    │       ├── render.rs   # Terminal Renderer, Markdown, Spinners
+    │       ├── init.rs     # Repo Initialization, Auto-detection
+    │       └── input.rs    # Vim-mode Terminal Line Editor
+    ├── plugins/            # Plugin System (2 Dateien + bundled)
+    │   └── src/
+    │       ├── lib.rs      # Full Plugin System
+    │       └── hooks.rs    # Hook Execution
+    ├── lsp/                # LSP Layer (5 Dateien)
+    │   └── src/
+    │       ├── lib.rs      # LSP Re-exports
+    │       ├── client.rs   # JSON-RPC over stdio
+    │       ├── manager.rs  # Multi-server Manager
+    │       ├── types.rs    # LSP Context Enrichment
+    │       └── error.rs    # LSP Error Types
+    ├── server/             # Server Layer (1 Datei)
+    │   └── src/
+    │       └── lib.rs      # Axum HTTP API, SSE Streaming
+    └── compat-harness/     # Compat-Harness (1 Datei)
+        └── src/
+            └── lib.rs      # Upstream TS Source Extraction
+```
+
+---
+
+## API Layer
+
+Der API Layer abstrahiert den Zugriff auf verschiedene LLM-Provider:
+
+```rust
+// Provider Trait
+pub trait Provider {
+    async fn stream(&self, request: MessageRequest) -> Result<StreamEvent>;
+    fn models(&self) -> Vec<ModelInfo>;
+}
+
+// OpenAI Provider
+let client = OpenSinApiClient::new(api_key, base_url);
+let events = client.stream(request).await?;
+```
+
+### Unterstützte Provider
+
+- **OpenSinApi** — OpenAI API via OCI Proxy
+- **OpenAICompat** — OpenAI/xAI kompatible Endpunkte
+
+---
+
+## Runtime Layer
+
+### Core Agent Loop
+
+```rust
+let mut conversation = Conversation::new(config);
+loop {
+    let response = client.stream(conversation.messages()).await?;
+    conversation.add_assistant(response);
+    
+    for tool_call in response.tool_calls {
+        let result = tools.execute(&tool_call).await?;
+        conversation.add_tool_result(tool_call.id, result);
+    }
+}
+```
+
+### Session Compaction
+
+Der Compaction-Algorithmus reduziert den Kontext wenn das Token-Limit erreicht wird:
+
+1. **Micro-Compact** — Einzelne Tool-Aufrufe zusammenfassen
+2. **Session Memory Compact** — Ältere Nachrichten komprimieren
+3. **Full Compact** — Gesamte Konversation zusammenfassen
+
+---
+
+## Built-in Tools (19)
+
+| Tool | Beschreibung |
+|------|-------------|
+| BashTool | Shell Command Execution |
+| ReadFileTool | Datei lesen |
+| WriteFileTool | Datei schreiben |
+| EditFileTool | Datei bearbeiten (Suchen/Ersetzen) |
+| GlobSearchTool | Datei-Globbing |
+| GrepSearchTool | Text-Suche |
+| WebFetchTool | URL-Inhalte abrufen |
+| WebSearchTool | Websuche |
+| TodoWriteTool | Todo-Liste verwalten |
+| SkillTool | Skill-Ausführung |
+| AgentTool | Sub-Agent spawnen |
+| ToolSearchTool | Deferred Tool Discovery |
+| NotebookEditTool | Jupyter Notebook bearbeiten |
+| SleepTool | Verzögerung |
+| BriefTool | Session-Zusammenfassung |
+| ConfigTool | Konfiguration (internal) |
+| StructuredOutputTool | Strukturierte Ausgabe |
+| REPLTool | REPL VM (internal) |
+| PowerShellTool | PowerShell Execution |
+
+---
+
+## CLI Layer
+
+Der Rust CLI (`sin-cli`) bietet einen vollständigen REPL-Modus:
+
+```bash
+# Interaktiver Modus
+sin
+
+# Mit Prompt
+sin "Erkläre die Codebasis"
+
+# Non-interactive
+sin --print "Review this file"
+
+# Mit Model
+sin --model opus "Analyse this"
+```
+
+### Features
+
+- **REPL** — Interaktive Eingabe mit History
+- **Vim-Mode** — Vim-style Line Editor
+- **Markdown Rendering** — Syntax Highlighting, Code Blocks
+- **Spinner** — Animierte Ladeanzeige
+- **Slash Commands** — 27+ integrierte Befehle
+
+---
+
+## Plugin System
+
+Plugins können Hooks, Commands, Agents und Skills registrieren:
+
+```json
+{
+  "name": "sin-mein-plugin",
+  "version": "1.0.0",
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "command": "python3 ${OPENSIN_PLUGIN_ROOT}/hooks/validate.py"
+      }
+    ]
+  }
+}
+```
+
+---
+
+## Bauen
+
+```bash
+cd packages/opensin-engine
+cargo build --release
+cargo test
+```
+
+---
+
+*Zuletzt aktualisiert: 2026-04-07 | OpenSIN-AI*