fix: map FlatEntityMaps and WorkspaceMigrationRunner exceptions to proper status codes on REST and GraphQL (#20494)

## Context

Calling `POST /rest/views` (and other metadata mutations) currently
returns a generic `500` for user-input failures:

Ex:
1. **Invalid `objectMetadataId`** —
`resolveEntityRelationUniversalIdentifiers` throws
`FlatEntityMapsException(RELATION_UNIVERSAL_IDENTIFIER_NOT_FOUND)`.
Should be `404`.
2. **Missing required field** (e.g. `icon`) — Postgres raises a `NOT
NULL` violation, wrapped as
`WorkspaceMigrationRunnerException(EXECUTION_FAILED)` carrying a
`QueryFailedError`. Should be `400`.

Neither was caught by `ViewRestApiExceptionFilter`, so both fell through
to `UnhandledExceptionFilter` and were emitted as `500`s without
reaching Sentry.
Same gap existed on most metadata GraphQL resolvers — only
`page-layout*` and `role` resolvers covered
`WorkspaceMigrationRunnerException` via
`WorkspaceMigrationGraphqlApiExceptionInterceptor`.

## Changes

### New filters

REST (`HttpExceptionHandlerService` + Sentry-aware):
- `FlatEntityMapsRestApiExceptionFilter` — maps
`RELATION_UNIVERSAL_IDENTIFIER_NOT_FOUND` / `ENTITY_NOT_FOUND` → `404`,
`ENTITY_ALREADY_EXISTS` → `409`, others → `500`.
- `WorkspaceMigrationRunnerRestApiExceptionFilter` — for
`EXECUTION_FAILED`, unwraps the underlying `metadata` /
`workspaceSchema` / `actionTranspilation` error; if it's a
`QueryFailedError` it gets remapped to `400` via
`HttpExceptionHandlerService`. `APPLICATION_NOT_FOUND` → `404`,
`DDL_LOCKED` → `503`, otherwise `500`.

GraphQL (graphql-errors + existing formatter):
- `FlatEntityMapsGraphqlApiExceptionFilter` — kept as the GraphQL-shaped
counterpart (`NotFoundError` / `InternalServerError`).
- `WorkspaceMigrationRunnerGraphqlApiExceptionFilter` — reuses
`workspaceMigrationRunnerExceptionFormatter` for parity with the
existing interceptor.

### Wiring

Filters are now declared **per controller / resolver** via `@UseFilters`
(no global `APP_FILTER` registration) so they participate in the normal
NestJS filter chain instead of being preempted by
`UnhandledExceptionFilter`.

REST:
- `view.controller.ts` — adds `FlatEntityMapsRestApiExceptionFilter` and
`WorkspaceMigrationRunnerRestApiExceptionFilter`.

GraphQL (14 resolvers, all that mutate flat entities):
- `FlatEntityMapsGraphqlApiExceptionFilter` added to: `view`,
`view-field`, `view-field-group`, `view-sort`, `view-group`,
`view-filter`, `view-filter-group`, `page-layout`, `page-layout-tab`,
`page-layout-widget`, `role`, `object-metadata`, `field-metadata`,
`index-metadata`.
- `WorkspaceMigrationRunnerGraphqlApiExceptionFilter` added to the same
list **except** the four already covered by
`WorkspaceMigrationGraphqlApiExceptionInterceptor` (`page-layout`,
`page-layout-tab`, `page-layout-widget`, `role`) — to avoid
double-handling.

## Why per-resolver / per-controller instead of global

Earlier attempt to register the filters globally via `APP_FILTER`
regressed: NestJS reverses the global filter list and
`selectExceptionFilterMetadata` is first-match-wins, so
`UnhandledExceptionFilter` (registered last via `app.useGlobalFilters`
in `main.ts`) ended up first in the iteration order and preempted every
domain-specific filter. The per-resolver / per-controller approach is
explicit and predictable.

## Before
<img width="953" height="450" alt="Screenshot 2026-05-12 at 15 31 40"
src="https://github.com/user-attachments/assets/3c3bc6a8-f6bc-4032-97d0-7243540cfb90"
/>


## After
<img width="1050" height="598" alt="Screenshot 2026-05-12 at 15 31 17"
src="https://github.com/user-attachments/assets/c66c9ce5-d1ea-4f1d-b2fe-07979e2261f7"
/>
<img width="1068" height="503" alt="Screenshot 2026-05-12 at 15 31 09"
src="https://github.com/user-attachments/assets/ddd9eed8-812b-47d6-96cb-b019b807991b"
/>

packages/twenty-server/src/engine/metadata-modules/front-component/controllers/front-component.controller.ts

@@ -20,16 +20,22 @@ import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.ent
 import { AuthWorkspace } from 'src/engine/decorators/auth/auth-workspace.decorator';
 import { NoPermissionGuard } from 'src/engine/guards/no-permission.guard';
 import { WorkspaceAuthGuard } from 'src/engine/guards/workspace-auth.guard';
+import { FlatEntityMapsRestApiExceptionFilter } from 'src/engine/metadata-modules/flat-entity/filters/flat-entity-maps-rest-api-exception.filter';
 import { FrontComponentRestApiExceptionFilter } from 'src/engine/metadata-modules/front-component/filters/front-component-rest-api-exception.filter';
 import {
   FrontComponentException,
   FrontComponentExceptionCode,
 } from 'src/engine/metadata-modules/front-component/front-component.exception';
 import { FrontComponentService } from 'src/engine/metadata-modules/front-component/front-component.service';
+import { WorkspaceMigrationRunnerRestApiExceptionFilter } from 'src/engine/workspace-manager/workspace-migration/filters/workspace-migration-runner-rest-api-exception.filter';
 
 @Controller('rest/front-components')
 @UseGuards(WorkspaceAuthGuard)
-@UseFilters(FrontComponentRestApiExceptionFilter)
+@UseFilters(
+  FrontComponentRestApiExceptionFilter,
+  FlatEntityMapsRestApiExceptionFilter,
+  WorkspaceMigrationRunnerRestApiExceptionFilter,
+)
 export class FrontComponentController {
   constructor(private readonly frontComponentService: FrontComponentService) {}