Add component parameter support and fix JS runtime

- Emit function parameters in component signature
- JS runtime passes props as positional arguments
- Remove incorrect return value handling (components call js_set_root internally)
- Enables: def Tabs(orientation=0)
- All tests passing (30/30)

ritz/llvm_codegen_signals.py

@@ -196,8 +196,17 @@ class SignalLLVMIRGenerator:
     def _emit_component(self, ir: dict[str, Any]) -> None:
         """Emit component render function."""
         component_name = ir["name"]
+
+        # Build parameter list
+        params = ir.get("params", [])
+        param_list = []
+        for param in params:
+            # For now, all params are i32
+            param_list.append(f"i32 %{param['name']}")
+        param_str = ", ".join(param_list) if param_list else ""
+
         self.lines.append("; Component render function")
-        self.lines.append(f"define void @render_{component_name}() {{")
+        self.lines.append(f"define void @render_{component_name}({param_str}) {{")
         self.lines.append("entry:")
 
         # Process component body (skip signals and functions, already handled)