Add Stationery and Stationery Dark themes with notebook chrome.

Manila folders, ruled chat, post-it nav, and folder tabs; dark variant uses Catppuccin Mocha colors with muted stickies and soft glows.

src/app/features/room/RoomInput.css.ts

@@ -0,0 +1,16 @@
+import { globalStyle, style } from '@vanilla-extract/css';
+import { color, config } from 'folds';
+import * as editorCss from '../../components/editor/Editor.css';
+
+export const RoomInputWrap = style({
+  width: '100%',
+});
+
+globalStyle(`${RoomInputWrap} .${editorCss.Editor}`, {
+  borderRadius: 0,
+  boxShadow: 'none',
+  borderTop: `${config.borderWidth.B300} solid ${color.SurfaceVariant.ContainerLine}`,
+  borderLeft: 'none',
+  borderRight: 'none',
+  borderBottom: 'none',
+});