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!

tests/test_codegen.py

@@ -0,0 +1,129 @@
+"""Tests for C code generation from IR."""
+
+
+
+def test_codegen_hello_world():
+    """Test generating C code for simple HelloWorld component."""
+    from ritz.codegen import generate_c_code
+
+    ir = {
+        "type": "component",
+        "name": "HelloWorld",
+        "args": [],
+        "body": [
+            {
+                "type": "with",
+                "element": {"tag": "P", "props": {}},
+                "body": [
+                    {
+                        "type": "yield",
+                        "value": {"type": "constant", "value": "Hello World"},
+                    }
+                ],
+            }
+        ],
+    }
+
+    c_code = generate_c_code(ir)
+
+    # Verify C code structure
+    assert "#include <emscripten.h>" in c_code
+    assert "void HelloWorld()" in c_code or "void render_HelloWorld()" in c_code
+
+    # Should create a P element
+    assert "create_element" in c_code or "createElement" in c_code
+    assert '"p"' in c_code or '"P"' in c_code.lower()
+
+    # Should create text node
+    assert '"Hello World"' in c_code
+    assert "create_text" in c_code or "createTextNode" in c_code or "set_text_content" in c_code
+
+
+def test_codegen_with_props():
+    """Test generating C code for element with props."""
+    from ritz.codegen import generate_c_code
+
+    ir = {
+        "type": "component",
+        "name": "StyledDiv",
+        "args": [],
+        "body": [
+            {
+                "type": "with",
+                "element": {
+                    "tag": "Div",
+                    "props": {
+                        "class_": {"type": "constant", "value": "container"},
+                        "id": {"type": "constant", "value": "main"},
+                    },
+                },
+                "body": [{"type": "yield", "value": {"type": "constant", "value": "Content"}}],
+            }
+        ],
+    }
+
+    c_code = generate_c_code(ir)
+
+    # Should set attributes
+    assert "set_attribute" in c_code or "setAttribute" in c_code
+    assert '"class"' in c_code or '"className"' in c_code
+    assert '"container"' in c_code
+    assert '"id"' in c_code
+    assert '"main"' in c_code
+
+
+def test_codegen_nested_elements():
+    """Test generating C code for nested elements."""
+    from ritz.codegen import generate_c_code
+
+    ir = {
+        "type": "component",
+        "name": "Nested",
+        "args": [],
+        "body": [
+            {
+                "type": "with",
+                "element": {"tag": "Div", "props": {}},
+                "body": [
+                    {
+                        "type": "with",
+                        "element": {"tag": "P", "props": {}},
+                        "body": [
+                            {"type": "yield", "value": {"type": "constant", "value": "Inner"}}
+                        ],
+                    }
+                ],
+            }
+        ],
+    }
+
+    c_code = generate_c_code(ir)
+
+    # Should have append_child calls to build hierarchy
+    assert "append_child" in c_code or "appendChild" in c_code
+
+
+def test_codegen_includes_runtime_functions():
+    """Test that generated C code includes necessary runtime declarations."""
+    from ritz.codegen import generate_c_code
+
+    ir = {
+        "type": "component",
+        "name": "Simple",
+        "args": [],
+        "body": [
+            {
+                "type": "with",
+                "element": {"tag": "P", "props": {}},
+                "body": [{"type": "yield", "value": {"type": "constant", "value": "test"}}],
+            }
+        ],
+    }
+
+    c_code = generate_c_code(ir)
+
+    # Should include emscripten
+    assert "#include <emscripten.h>" in c_code
+
+    # Should have EMSCRIPTEN_KEEPALIVE for exported function
+    assert "EMSCRIPTEN_KEEPALIVE" in c_code