refactor: rename navbar components and dimensions to sidebar for improved semantic consistency

apps/web/src/apps/shell-demo/index.tsx

@@ -139,8 +139,8 @@ export default function ShellDemo() {
               </Group>
             ),
             header: <MockHeader />,
-            navbarMobile: <MockMobileDrawer />,
-            navbar: !withDoubleSidebar ? (
+            sidebarMobile: <MockMobileDrawer />,
+            sidebar: !withDoubleSidebar ? (
               <Box p="md" h="100%" bg="grape.1" c="grape.9" style={{ borderRight: '1px solid var(--mantine-color-grape-3)' }}>
                 <Text fw={700} mb="sm">Mock Standard Navbar (bg="grape.1")</Text>
                 <Stack gap="xs">
@@ -151,7 +151,7 @@ export default function ShellDemo() {
                 </Stack>
               </Box>
             ) : undefined,
-            navbarRail: withDoubleSidebar ? (
+            sidebarRail: withDoubleSidebar ? (
               <Stack align="center" gap="lg" pt="md" h="100%" bg="orange.1" c="orange.9">
                 <Text size="xs" fw={700} style={{ writingMode: 'vertical-rl', transform: 'rotate(180deg)' }}>
                   Mock Rail (bg="orange.1")
@@ -161,7 +161,7 @@ export default function ShellDemo() {
                 <SettingsIcon size={24} />
               </Stack>
             ) : undefined,
-            navbarPanel: withDoubleSidebar ? (
+            sidebarPanel: withDoubleSidebar ? (
               <Box p="md" h="100%" bg="grape.1" c="grape.9" style={{ borderRight: '1px solid var(--mantine-color-grape-3)' }}>
                 <Text fw={700} mb="sm">Mock Panel (bg="grape.1")</Text>
                 <Stack gap="xs">