release(v0.2.0): streaming, MCP protocol, Browser Hand, security enhancements

## Major Features

### Streaming Response System
- Implement LlmDriver trait with `stream()` method returning async Stream
- Add SSE parsing for Anthropic and OpenAI API streaming
- Integrate Tauri event system for frontend streaming (`stream:chunk` events)
- Add StreamChunk types: Delta, ToolStart, ToolEnd, Complete, Error

### MCP Protocol Implementation
- Add MCP JSON-RPC 2.0 types (mcp_types.rs)
- Implement stdio-based MCP transport (mcp_transport.rs)
- Support tool discovery, execution, and resource operations

### Browser Hand Implementation
- Complete browser automation with Playwright-style actions
- Support Navigate, Click, Type, Scrape, Screenshot, Wait actions
- Add educational Hands: Whiteboard, Slideshow, Speech, Quiz

### Security Enhancements
- Implement command whitelist/blacklist for shell_exec tool
- Add SSRF protection with private IP blocking
- Create security.toml configuration file

## Test Improvements
- Fix test import paths (security-utils, setup)
- Fix vi.mock hoisting issues with vi.hoisted()
- Update test expectations for validateUrl and sanitizeFilename
- Add getUnsupportedLocalGatewayStatus mock

## Documentation Updates
- Update architecture documentation
- Improve configuration reference
- Add quick-start guide updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

desktop/tests/config-parser.test.ts

@@ -8,8 +8,9 @@ import { describe, it, expect } from 'vitest';
 import {
   configParser,
   ConfigParseError,
+  ConfigValidationFailedError,
 } from '../src/lib/config-parser';
-import type { OpenFangConfig, ConfigValidationError } from '../src/types/config';
+import type { OpenFangConfig } from '../src/types/config';
 
 describe('configParser', () => {
   const validToml = `
@@ -156,7 +157,7 @@ host = "127.0.0.1"
 # missing port
 `;
 
-      expect(() => configParser.parseAndValidate(invalidToml)).toThrow(ConfigValidationError);
+      expect(() => configParser.parseAndValidate(invalidToml)).toThrow(ConfigValidationFailedError);
     });
   });