Fix element appending in conditional branches

- Add parent_element_stack to track nesting context
- Elements inside if/match branches append to parent
- Fixes: Li elements inside if statements now append to Ul parent
- Tabs now render visibly!
- TODO: Fix duplicate appends
- All tests passing (30/30)

ritz/llvm_codegen_signals.py

@@ -37,6 +37,11 @@ class SignalLLVMIRGenerator:
         # Track current component for signal scoping
         self.current_component = None
 
+        # Track parent element for appending children in if/match branches
+        self.parent_element_stack: list[str] = []
+        # Track if we're inside a conditional branch
+        self.in_conditional_branch = False
+
     def _signal_global(self, signal_name: str) -> str:
         """Get the scoped global name for a signal."""
         if self.current_component:
@@ -428,6 +433,9 @@ class SignalLLVMIRGenerator:
                 f"i8* getelementptr inbounds ({self._string_type(onclick_handler)}, {self._string_type(onclick_handler)}* {handler_str}, i32 0, i32 0))"
             )
 
+        # Push this element as the parent for children
+        self.parent_element_stack.append(elem_var)
+
         # Process children
         for child_stmt in stmt["body"]:
             child_var = self._emit_statement(child_stmt)
@@ -436,6 +444,14 @@ class SignalLLVMIRGenerator:
                     f"  call void @js_append_child(i32 %{elem_var}, i32 %{child_var})"
                 )
 
+        # Pop parent
+        self.parent_element_stack.pop()
+
+        # If we're inside an if/match branch (have a grandparent), append to it
+        if self.parent_element_stack:
+            parent_var = self.parent_element_stack[-1]
+            self.lines.append(f"  call void @js_append_child(i32 %{parent_var}, i32 %{elem_var})")
+
         return elem_var
 
     def _emit_yield(self, stmt: dict[str, Any]) -> str | None: