docs: add VitePress documentation site

- Add docs directory with VitePress configuration
- Add GitHub Actions workflow for docs build and deploy
- Support bilingual (English/Chinese) documentation
- Include search, custom theme, and responsive design

docs/features/memory.md

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+# Memory System
+
+## One-Liner
+
+**The Memory System is a cross-session knowledge persistence mechanism** — Stores project context, decisions, and learnings so AI remembers across sessions without re-explanation.
+
+---
+
+## Pain Points Solved
+
+| Pain Point | Current State | Memory System Solution |
+|------------|---------------|------------------------|
+| **Cross-session amnesia** | New session requires re-explaining project | Persistent memory across sessions |
+| **Lost decisions** | Architecture decisions forgotten | Decision log persists |
+| **Repeated explanations** | Same context explained multiple times | Memory auto-injection |
+| **Knowledge silos** | Each developer maintains own context | Shared team memory |
+
+---
+
+## vs Traditional Methods
+
+| Dimension | CLAUDE.md | Notes | **Memory System** |
+|-----------|-----------|-------|-------------------|
+| Persistence | Static file | Manual | **Auto-extracted from sessions** |
+| Search | Text search | Folder search | **Semantic vector search** |
+| Updates | Manual edit | Manual note | **Auto-capture from conversations** |
+| Sharing | Git | Manual | **Auto-sync via workflow** |
+
+---
+
+## Core Concepts
+
+| Concept | Description | Location |
+|---------|-------------|----------|
+| **Core Memory** | Persistent project knowledge | `~/.claude/memory/` |
+| **Session Memory** | Current session context | `.workflow/.memory/` |
+| **Memory Entry** | Individual knowledge item | JSONL format |
+| **Memory Index** | Searchable index | Embedding-based |
+
+---
+
+## Usage
+
+### Viewing Memory
+
+```bash
+ccw memory list
+ccw memory search "authentication"
+```
+
+### Memory Categories
+
+- **Project Context**: Architecture, tech stack, patterns
+- **Decisions**: ADRs, design choices
+- **Learnings**: What worked, what didn't
+- **Conventions**: Coding standards, naming
+
+---
+
+## Configuration
+
+```json
+// ~/.claude/cli-settings.json
+{
+  "memory": {
+    "enabled": true,
+    "maxEntries": 1000,
+    "autoCapture": true,
+    "embeddingModel": "text-embedding-3-small"
+  }
+}
+```
+
+---
+
+## Related Links
+
+- [Spec System](/features/spec) - Constraint injection
+- [CLI Call](/features/cli) - Command line invocation
+- [CodexLens](/features/codexlens) - Code indexing