feat: navigation

backend/uframe/ir.py

@@ -361,6 +361,36 @@ class StateDecl(IRNode):
 # Components (Phase 8)
 # ---------------------------------------------------------------------------
 
+# ---------------------------------------------------------------------------
+# Navigation nodes
+# ---------------------------------------------------------------------------
+
+@dataclass
+class NavItem:
+    """A single item in a navigation bar."""
+    kind: str = "item"          # "item", "separator", "heading"
+    label: str = ""
+    dest: str = ""
+    active: bool = False
+    children: list["NavItem"] = field(default_factory=list)
+
+
+@dataclass
+class HNav(IRNode):
+    """Horizontal navigation bar."""
+    nav_style: str = "bar"      # bar, tabs, pills, breadcrumb, underline
+    items: list[NavItem] = field(default_factory=list)
+    compact: bool = False
+
+
+@dataclass
+class VNav(IRNode):
+    """Vertical navigation panel."""
+    nav_style: str = "list"     # list, boxed, tree, sidebar, minimal
+    nav_width: int = 0          # 0 = auto-fit
+    items: list[NavItem] = field(default_factory=list)
+
+
 @dataclass
 class ImageNode(IRNode):
     """Image converted to character art."""