feat: add plugin button and navigation slots for enhanced plugin integration across various components

src/app/pages/client/sidebar/SettingsTab.tsx

@@ -13,6 +13,7 @@ import { useUserProfile } from '../../../hooks/useUserProfile';
 import { Modal500 } from '../../../components/Modal500';
 import { AccountSwitcher } from '../../../components/account-switcher';
 import { stopPropagation } from '../../../utils/keyboard';
+import { PluginButtonSlot } from '../../../features/settings/plugins/PluginButtonSlot';
 import { getLoginPath } from '../../pathUtils';
 import { logoutClient } from '../../../../client/initMatrix';
 import { CustomStatusDialog } from '../../../components/custom-status';
@@ -110,6 +111,10 @@ export function SettingsTab() {
                 </MenuItem>
               </Box>
               <Line variant="Surface" size="300" />
+              <Box direction="Row" gap="100" style={{ padding: config.space.S100 }}>
+                <PluginButtonSlot location="user-menu" />
+              </Box>
+              <Line variant="Surface" size="300" />
               <Box direction="Column" gap="100" style={{ padding: config.space.S100 }}>
                 <MenuItem
                   onClick={() => {