feat: standalone MCP server (ra-h-mcp-server)

- Added apps/mcp-server-standalone/ with direct SQLite access
- Works without RA-OS app running
- Install via: npx ra-h-mcp-server
- Updated docs/8_mcp.md with setup instructions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/mcp-server-standalone/README.md

@@ -0,0 +1,74 @@
+# RA-H MCP Server
+
+Connect Claude Code and Claude Desktop to your RA-H knowledge base. Direct SQLite access - works without the RA-H app running.
+
+## Install
+
+```bash
+npx ra-h-mcp-server
+```
+
+That's it. No manual setup required.
+
+## Configure Claude Code / Claude Desktop
+
+Add to your Claude config (`~/.claude.json` or Claude Desktop settings):
+
+```json
+{
+  "mcpServers": {
+    "ra-h": {
+      "command": "npx",
+      "args": ["ra-h-mcp-server"]
+    }
+  }
+}
+```
+
+Restart Claude. Done.
+
+## Requirements
+
+- Node.js 18+
+- RA-H database at `~/Library/Application Support/RA-H/db/rah.sqlite`
+  - Run the RA-H desktop app once to create it
+
+## Environment Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `RAH_DB_PATH` | ~/Library/Application Support/RA-H/db/rah.sqlite | Database path |
+
+## Available Tools
+
+| Tool | Description |
+|------|-------------|
+| `rah_add_node` | Create a new node |
+| `rah_search_nodes` | Search nodes by keyword |
+| `rah_get_nodes` | Load nodes by ID |
+| `rah_update_node` | Update an existing node |
+| `rah_create_edge` | Create connection between nodes |
+| `rah_query_edges` | Find edges for a node |
+| `rah_list_dimensions` | List all dimensions |
+| `rah_create_dimension` | Create a dimension |
+| `rah_update_dimension` | Update/rename a dimension |
+| `rah_delete_dimension` | Delete a dimension |
+
+## What's NOT Included
+
+This is a lightweight CRUD server. Advanced features are handled by the main app:
+
+- Embedding generation
+- AI-powered edge inference
+- Content extraction (URL, YouTube, PDF)
+- Real-time SSE events
+
+## Testing
+
+```bash
+# Test database connection
+node -e "const {initDatabase,query}=require('./services/sqlite-client');initDatabase();console.log(query('SELECT COUNT(*) as c FROM nodes')[0].c,'nodes')"
+
+# Run the server
+node index.js
+```