fix: Enable Lingui recommended rules and fix all translation violations (#14133)

- Enable lingui/no-single-variables-to-translate and all other
recommended Lingui rules
- Fix single variable translation patterns (t`${variable}` → variable)
- Fix expression-in-message violations by extracting variables
- Fix t-call-in-function violations by moving translations inside
functions
- Update ESLint configs to use linguiPlugin.configs['flat/recommended']
- Clean up unused imports and improve translation patterns

packages/twenty-server/src/engine/metadata-modules/flat-object-metadata/utils/run-flat-object-metadata-validators.util.ts

@@ -1,3 +1,5 @@
+import { t } from '@lingui/core/macro';
+
 import { type FlatObjectMetadataValidationError } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata-validation-error.type';
 import { ObjectMetadataExceptionCode } from 'src/engine/metadata-modules/object-metadata/object-metadata.exception';
 import { type FlatMetadataValidator } from 'src/engine/metadata-modules/types/flat-metadata-validator.type';
@@ -15,7 +17,7 @@ export const runFlatObjectMetadataValidators = <T>({
     if (isInvalid) {
       return {
         code: ObjectMetadataExceptionCode.INVALID_OBJECT_INPUT,
-        message,
+        message: t(message),
         value: elementToValidate,
       };
     }