Complete linaria migration (#18361)

## Summary

Completes the migration of the frontend styling system from **Emotion**
(`@emotion/styled`, `@emotion/react`) to **Linaria** (`@linaria/react`,
`@linaria/core`), a zero-runtime CSS-in-JS library where styles are
extracted at build time.

This is the final step of the migration — all ~494 files across
`twenty-front`, `twenty-ui`, `twenty-website`, and `twenty-sdk` are now
fully converted.

## Changes

### Styling Migration (across ~480 component files)
- Replaced all `@emotion/styled` imports with `@linaria/react`
- Converted runtime theme access patterns (`({ theme }) => theme.x.y`)
to build-time `themeCssVariables` CSS custom properties
- Replaced `useTheme()` hook (from Emotion) with
`useContext(ThemeContext)` where runtime theme values are still needed
(e.g., passing colors to non-CSS props like icon components)
- Removed `@emotion/react` `css` helper usages in favor of Linaria
template literals

### Dependency & Configuration Changes
- **Removed**: `@emotion/react`, `@emotion/styled` from root
`package.json`
- **Added**: `@wyw-in-js/babel-preset`, `next-with-linaria` (for
twenty-website SSR support)
- Updated Nx generator defaults from `@emotion/styled` to
`@linaria/react` in `nx.json`
- Simplified `vite.config.ts` (removed Emotion-specific configuration)
- Updated `twenty-website/next.config.js` to use `next-with-linaria` for
SSR Linaria support

### Storybook & Testing
- Removed `ThemeProvider` from Emotion in Storybook previews
(`twenty-front`, `twenty-sdk`)
- Now relies solely on `ThemeContextProvider` for theme injection

### Documentation
- Removed the temporary `docs/emotion-to-linaria-migration-plan.md`
(migration complete)
- Updated `CLAUDE.md` and `README.md` to reflect Linaria as the styling
stack
- Updated frontend style guide docs across all locales

## How it works

Linaria extracts styles at build time via the `@wyw-in-js/vite` plugin.
All expressions in `styled` template literals must be **statically
evaluable** — no runtime theme objects or closures over component state.

- **Static styles** use `themeCssVariables` which map to CSS custom
properties (`var(--theme-color-x)`)
- **Runtime theme access** (for non-CSS use cases like icon `color`
props) uses `useContext(ThemeContext)` instead of Emotion's `useTheme()`

packages/twenty-front/src/modules/settings/admin-panel/components/SettingsAdminGeneral.tsx

@@ -5,7 +5,7 @@ import { useSnackBar } from '@/ui/feedback/snack-bar-manager/hooks/useSnackBar';
 import { SettingsTextInput } from '@/ui/input/components/SettingsTextInput';
 import { TabList } from '@/ui/layout/tab-list/components/TabList';
 import { DEFAULT_WORKSPACE_LOGO } from '@/ui/navigation/navigation-drawer/constants/DefaultWorkspaceLogo';
-import styled from '@emotion/styled';
+import { styled } from '@linaria/react';
 import { t } from '@lingui/core/macro';
 import { isNonEmptyString } from '@sniptt/guards';
 import { useAtomState } from '@/ui/utilities/state/jotai/hooks/useAtomState';
@@ -30,12 +30,13 @@ import {
 } from 'twenty-ui/display';
 import { Button } from 'twenty-ui/input';
 import { Section } from 'twenty-ui/layout';
+import { themeCssVariables } from 'twenty-ui/theme-constants';
 
 const StyledContainer = styled.div`
   align-items: center;
   display: flex;
   flex-direction: row;
-  gap: ${({ theme }) => theme.spacing(2)};
+  gap: ${themeCssVariables.spacing[2]};
 `;
 
 export const SettingsAdminGeneral = () => {

packages/twenty-front/src/modules/settings/admin-panel/components/SettingsAdminTabSkeletonLoader.tsx

@@ -1,10 +1,11 @@
-import { useTheme } from '@emotion/react';
+import { useContext } from 'react';
 import Skeleton, { SkeletonTheme } from 'react-loading-skeleton';
 
 import { SKELETON_LOADER_HEIGHT_SIZES } from '@/activities/components/SkeletonLoader';
+import { ThemeContext } from 'twenty-ui/theme';
 
 export const SettingsAdminTabSkeletonLoader = () => {
-  const theme = useTheme();
+  const { theme } = useContext(ThemeContext);
   return (
     <SkeletonTheme
       baseColor={theme.background.tertiary}

packages/twenty-front/src/modules/settings/admin-panel/components/SettingsAdminTableCard.tsx

@@ -2,28 +2,30 @@ import { Table } from '@/ui/layout/table/components/Table';
 import { TableBody } from '@/ui/layout/table/components/TableBody';
 import { TableCell } from '@/ui/layout/table/components/TableCell';
 import { TableRow } from '@/ui/layout/table/components/TableRow';
-import { useTheme } from '@emotion/react';
-import styled from '@emotion/styled';
+import { styled } from '@linaria/react';
+import { useContext } from 'react';
 import { isDefined } from 'twenty-shared/utils';
 import { type IconComponent } from 'twenty-ui/display';
 import { Card } from 'twenty-ui/layout';
+import { ThemeContext } from 'twenty-ui/theme';
+import { themeCssVariables } from 'twenty-ui/theme-constants';
 
 const StyledCard = styled(Card)`
-  background-color: ${({ theme }) => theme.background.secondary};
-  border: 1px solid ${({ theme }) => theme.border.color.medium};
+  background-color: ${themeCssVariables.background.secondary};
+  border: 1px solid ${themeCssVariables.border.color.medium};
 `;
 
 const StyledTableRow = styled(TableRow)`
-  height: ${({ theme }) => theme.spacing(6)};
+  height: ${themeCssVariables.spacing[6]};
 `;
 
 const StyledTableCellLabel = styled(TableCell)<{
   align?: 'left' | 'center' | 'right';
 }>`
-  color: ${({ theme }) => theme.font.color.tertiary};
-  height: ${({ theme }) => theme.spacing(6)};
+  color: ${themeCssVariables.font.color.tertiary};
+  height: ${themeCssVariables.spacing[6]};
   display: flex;
-  gap: ${({ theme }) => theme.spacing(2)};
+  gap: ${themeCssVariables.spacing[2]};
   justify-content: ${({ align }) =>
     align === 'right'
       ? 'flex-end'
@@ -36,9 +38,9 @@ const StyledTableCellValue = styled(TableCell)<{
   align?: 'left' | 'center' | 'right';
   clickable?: boolean;
 }>`
-  color: ${({ theme }) => theme.font.color.primary};
+  color: ${themeCssVariables.font.color.primary};
   cursor: ${({ clickable }) => (clickable ? 'pointer' : 'default')};
-  height: ${({ theme }) => theme.spacing(6)};
+  height: ${themeCssVariables.spacing[6]};
   justify-content: ${({ align }) =>
     align === 'left'
       ? 'flex-start'
@@ -71,7 +73,7 @@ export const SettingsAdminTableCard = ({
   valueAlign = 'left',
   className,
 }: SettingsAdminTableCardProps) => {
-  const theme = useTheme();
+  const { theme } = useContext(ThemeContext);
 
   return (
     <StyledCard rounded={rounded} className={className}>

packages/twenty-front/src/modules/settings/admin-panel/components/SettingsAdminVersionDisplay.tsx

@@ -1,5 +1,6 @@
-import styled from '@emotion/styled';
+import { styled } from '@linaria/react';
 import { t } from '@lingui/core/macro';
+import { themeCssVariables } from 'twenty-ui/theme-constants';
 
 type SettingsAdminVersionDisplayProps = {
   version: string | undefined | null;
@@ -9,23 +10,23 @@ type SettingsAdminVersionDisplayProps = {
 
 const StyledActionLink = styled.a`
   align-items: center;
-  color: ${({ theme }) => theme.font.color.primary};
+  color: ${themeCssVariables.font.color.primary};
   display: flex;
-  font-size: ${({ theme }) => theme.font.size.sm};
-  font-weight: ${({ theme }) => theme.font.weight.regular};
-  gap: ${({ theme }) => theme.spacing(1)};
+  font-size: ${themeCssVariables.font.size.sm};
+  font-weight: ${themeCssVariables.font.weight.regular};
+  gap: ${themeCssVariables.spacing[1]};
   text-decoration: none;
 
   :hover {
-    color: ${({ theme }) => theme.font.color.primary};
+    color: ${themeCssVariables.font.color.primary};
     cursor: pointer;
   }
 `;
 
 const StyledSpan = styled.span`
-  color: ${({ theme }) => theme.font.color.primary};
-  font-size: ${({ theme }) => theme.font.size.sm};
-  font-weight: ${({ theme }) => theme.font.weight.regular};
+  color: ${themeCssVariables.font.color.primary};
+  font-size: ${themeCssVariables.font.size.sm};
+  font-weight: ${themeCssVariables.font.weight.regular};
 `;
 
 export const SettingsAdminVersionDisplay = ({

packages/twenty-front/src/modules/settings/admin-panel/components/SettingsAdminWorkspaceContent.tsx

@@ -15,7 +15,7 @@ import { TableCell } from '@/ui/layout/table/components/TableCell';
 import { TableHeader } from '@/ui/layout/table/components/TableHeader';
 import { TableRow } from '@/ui/layout/table/components/TableRow';
 import { DEFAULT_WORKSPACE_LOGO } from '@/ui/navigation/navigation-drawer/constants/DefaultWorkspaceLogo';
-import styled from '@emotion/styled';
+import { styled } from '@linaria/react';
 import { useLingui } from '@lingui/react/macro';
 import { isNonEmptyString } from '@sniptt/guards';
 import { useAtomStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomStateValue';
@@ -33,6 +33,7 @@ import {
 } from 'twenty-ui/display';
 import { Button, Toggle } from 'twenty-ui/input';
 import { Section } from 'twenty-ui/layout';
+import { themeCssVariables } from 'twenty-ui/theme-constants';
 import { REACT_APP_SERVER_BASE_URL } from '~/config';
 import {
   type FeatureFlagKey,
@@ -47,12 +48,12 @@ type SettingsAdminWorkspaceContentProps = {
 const StyledContainer = styled.div`
   display: flex;
   flex-direction: column;
-  gap: ${({ theme }) => theme.spacing(3)};
-  margin-top: ${({ theme }) => theme.spacing(6)};
+  gap: ${themeCssVariables.spacing[3]};
+  margin-top: ${themeCssVariables.spacing[6]};
 `;
 
 const StyledButtonContainer = styled.div`
-  margin-top: ${({ theme }) => theme.spacing(3)};
+  margin-top: ${themeCssVariables.spacing[3]};
 `;
 
 export const SettingsAdminWorkspaceContent = ({