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!

examples/ritz-debug.js

@@ -0,0 +1,83 @@
+/**
+ * Ritz Debug Bar Controller
+ */
+
+class RitzDebug {
+    constructor() {
+        this.debugBar = document.getElementById('ritz-debug');
+        this.isOpen = false;
+
+        // Setup keyboard shortcut (Ctrl+`)
+        document.addEventListener('keydown', (e) => {
+            if (e.ctrlKey && e.key === '`') {
+                e.preventDefault();
+                this.toggle();
+            }
+        });
+
+        // Show hint on first load
+        this.showHint();
+    }
+
+    toggle() {
+        this.isOpen = !this.isOpen;
+
+        if (this.debugBar) {
+            if (this.isOpen) {
+                this.debugBar.classList.remove('hidden');
+                document.body.classList.add('debug-open');
+            } else {
+                this.debugBar.classList.add('hidden');
+                document.body.classList.remove('debug-open');
+            }
+        }
+    }
+
+    open() {
+        this.isOpen = true;
+        if (this.debugBar) {
+            this.debugBar.classList.remove('hidden');
+            document.body.classList.add('debug-open');
+        }
+    }
+
+    close() {
+        this.isOpen = false;
+        if (this.debugBar) {
+            this.debugBar.classList.add('hidden');
+            document.body.classList.remove('debug-open');
+        }
+    }
+
+    showHint() {
+        // Show toggle hint for 3 seconds
+        const hint = document.createElement('div');
+        hint.className = 'debug-toggle-hint';
+        hint.textContent = 'Press Ctrl+` to toggle debug';
+        document.body.appendChild(hint);
+
+        setTimeout(() => {
+            hint.remove();
+        }, 3000);
+    }
+
+    log(message, type = 'info') {
+        const status = document.getElementById('status');
+        if (status) {
+            status.textContent = message;
+            status.className = 'status ' + type;
+        }
+        console.log(`[Ritz] ${message}`);
+    }
+}
+
+// Initialize debug controller
+const ritzDebug = new RitzDebug();
+
+// Export
+if (typeof module !== 'undefined' && module.exports) {
+    module.exports = RitzDebug;
+} else {
+    window.RitzDebug = RitzDebug;
+    window.ritzDebug = ritzDebug;
+}