Implement Python → LLVM IR → WASM reactive framework

MAJOR ACHIEVEMENT: Full working reactive framework!

## What's Working

✅ Python → AST → Ritz IR → LLVM IR → WASM pipeline
✅ Reactive signals stored in WASM memory (@signal_name = global i32)
✅ Event handlers exported from WASM and callable from JS
✅ Clean runtime with RitzLoader and debug tools
✅ Two working examples: HelloWorld and HighFive counter

## Core Components

### Parser (ritz/parser.py)
- Uses Python's ast module to parse components
- Handles @component decorator, signals, event handlers
- Supports yield, with statements, f-strings, augmented assignment (+=)
- Clean syntax: from ritz.syntax import *

### LLVM IR Code Generator (ritz/llvm_codegen_signals.py)
- Generates LLVM IR directly (not C!)
- Signals as global variables in WASM memory
- Exports getter/setter functions for each signal
- Exports event handler functions for JS to call
- UTF-8 string handling

### Build System (ritz/build.py)
- Python → AST → IR → LLVM IR → clang --target=wasm32 → WASM
- Saves intermediate .ll files for inspection
- Debug symbols support (-g flag)

### Runtime (runtime/ritz-runtime.js)
- RitzRuntime class: DOM bridge for WASM
- RitzLoader class: Simplified component loading
- Debug bar with Ctrl+` toggle
- Signal updates trigger DOM updates

## Examples

### HelloWorld.py
Simple static content - renders <p>Hello World</p>

### HighFive.py
Reactive counter with:
- Signal in WASM memory (high_fives = signal(0))
- Event handler (increment function)
- DOM updates on signal change

## Test Coverage

- 4 parser tests (all passing)
- 4 LLVM codegen tests (all passing)
- 4 signal parsing tests (all passing)
- Code formatted with black and ruff

## Next Steps

- <script type="text/ritz"> in-browser compilation
- Better signal-to-DOM binding tracking
- More complex examples (TodoMVC, forms, lists)
- Playwright browser tests

---

This is a genuinely innovative framework: write Python, compile to WASM,
run with reactive signals in WASM memory. No virtual DOM, no transpilation,
just compiled Python with fine-grained reactivity.

🎉 Python → WASM → Reactive UI is REAL!

serve.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+"""Simple dev server for testing Ritz components."""
+
+import http.server
+import socketserver
+from pathlib import Path
+
+PORT = 8111
+DIRECTORY = Path(__file__).parent / "examples"
+
+
+class WASMHandler(http.server.SimpleHTTPRequestHandler):
+    """HTTP handler with proper WASM MIME type."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, directory=str(DIRECTORY), **kwargs)
+
+    def end_headers(self):
+        # Set CORS headers for local development
+        self.send_header("Access-Control-Allow-Origin", "*")
+        # Ensure WASM has correct MIME type
+        if self.path.endswith(".wasm"):
+            self.send_header("Content-Type", "application/wasm")
+        super().end_headers()
+
+
+if __name__ == "__main__":
+    socketserver.TCPServer.allow_reuse_address = True
+    with socketserver.TCPServer(("", PORT), WASMHandler) as httpd:
+        print("🚀 Ritz Dev Server")
+        print(f"   Serving: {DIRECTORY}")
+        print(f"   URL: http://localhost:{PORT}")
+        print(f"\n   Open http://localhost:{PORT}/index.html in your browser")
+        print("\n   Press Ctrl+C to stop")
+        try:
+            httpd.serve_forever()
+        except KeyboardInterrupt:
+            print("\n\n👋 Server stopped")