Deprecate runtime theme objects in favor of CSS variables (#18402)

## Summary

- **Eliminate `ICON_SIZES` / `ICON_STROKES` constants**: all icon
dimensions are now resolved at runtime via
`resolveThemeVariableAsNumber(themeCssVariables.icon.size.X)`, ensuring
values always come from computed CSS variables
- **No more consumer imports from `twenty-ui/theme`**: moved
`ColorSchemeContext`, `ColorSchemeProvider`, `ThemeColor`,
`MAIN_COLOR_NAMES`, `getNextThemeColor`, `AnimationDuration` to
`twenty-ui/theme-constants`
- **Remove `ThemeContext` / `ThemeContextProvider` / `ThemeProvider` /
`ThemeType`**: replaced across ~300 files with `themeCssVariables` (for
CSS contexts) or `resolveThemeVariable` / `resolveThemeVariableAsNumber`
(for JS runtime values)
- **Simplify provider chain**: only `ColorSchemeProvider` remains — it
toggles `light`/`dark` class on `document.documentElement` and provides
`colorScheme` via React context
- **Fix pre-existing test failures**: `useIcons.test.ts`
(non-configurable ES module spy) and
`turnRecordFilterGroupIntoGqlOperationFilter.test.ts`
(`Omit<RecordFilter, 'id'>` type mismatch)

### Theme access pattern (before → after)

| Context | Before | After |
|---------|--------|-------|
| CSS (Linaria) | `${({ theme }) => theme.font.color.primary}` |
`${themeCssVariables.font.color.primary}` |
| JS runtime (icon size, animation) | `theme.icon.size.md` /
`ICON_SIZES.md` |
`resolveThemeVariableAsNumber(themeCssVariables.icon.size.md)` |
| Color scheme check | `theme.name === 'dark'` |
`useContext(ColorSchemeContext).colorScheme === 'dark'` |

packages/twenty-sdk/src/front-component-renderer/__stories__/example-sources/twenty-ui-example.front-component.tsx

@@ -7,7 +7,6 @@ import {
   H2Title,
   Status,
   Tag,
-  THEME_LIGHT,
   ThemeProvider,
 } from 'twenty-sdk/ui';
 
@@ -34,7 +33,7 @@ const TwentyUiComponent = () => {
   const [count, setCount] = useState(0);
 
   return (
-    <ThemeProvider theme={THEME_LIGHT}>
+    <ThemeProvider colorScheme="light">
       <div data-testid="twenty-ui-component" style={CARD_STYLE}>
         <H2Title
           title="Twenty UI"

packages/twenty-sdk/src/front-component-renderer/host/components/FrontComponentRenderer.tsx

@@ -12,7 +12,7 @@ import {
 import { useMemo, useState } from 'react';
 import { isDefined } from 'twenty-shared/utils';
 
-import { type ThemeType, ThemeContextProvider } from 'twenty-ui/theme';
+import { ThemeProvider } from 'twenty-ui/theme-constants';
 import { FrontComponentWorkerEffect } from '../../remote/components/FrontComponentWorkerEffect';
 import { componentRegistry } from '../generated/host-component-registry';
 
@@ -23,7 +23,7 @@ type FrontComponentContentProps = {
   executionContext: FrontComponentExecutionContext;
   frontComponentHostCommunicationApi: FrontComponentHostCommunicationApi;
   onError: (error?: Error) => void;
-  theme: ThemeType;
+  colorScheme: 'light' | 'dark';
 };
 
 export const FrontComponentRenderer = ({
@@ -33,7 +33,7 @@ export const FrontComponentRenderer = ({
   executionContext,
   frontComponentHostCommunicationApi,
   onError,
-  theme,
+  colorScheme,
 }: FrontComponentContentProps) => {
   const [receiver, setReceiver] = useState<RemoteReceiver | null>(null);
   const [thread, setThread] = useState<ThreadWebWorker<
@@ -109,12 +109,12 @@ export const FrontComponentRenderer = ({
       )}
 
       {isDefined(receiver) && isExecutionContextInitialized && (
-        <ThemeContextProvider theme={theme}>
+        <ThemeProvider colorScheme={colorScheme}>
           <RemoteRootRenderer
             receiver={receiver}
             components={componentRegistry}
           />
-        </ThemeContextProvider>
+        </ThemeProvider>
       )}
     </>
   );