feat: kanban, calendar and group-by table layouts for dashboard view widgets (#22963)

## Context

Dashboard view widgets previously only rendered flat tables. This PR
ships the full feature: **Table with group-by**, **Kanban**, and
**Calendar** layouts for dashboard view widgets — server API + frontend,
end-to-end. (Originally staged as a 4-PR stack — #22966, #22967, #22968
— consolidated here per review.)

## Server / API

- **View typing.** Adds `KANBAN_WIDGET` and `CALENDAR_WIDGET` to
`ViewType` (following the `TABLE_WIDGET` precedent) so widget-backing
views keep their layout in `view.type` while staying excluded from
record-index pickers. Shared `getViewLayoutFromViewType()` maps widget
types to their base layout; `isWidgetViewType()` centralizes the
exclusions that were previously hardcoded per-site.
- **Migrations.** Two fast instance commands (**2.23**): `ALTER TYPE
core.view_type_enum ADD VALUE` for both values, and a widened
`CHK_VIEW_CALENDAR_INTEGRITY` constraint covering `CALENDAR_WIDGET`
(entity `@Check` updated for fresh installs).
- **Validation.** `FlatViewValidatorService` keys kanban/calendar
validation on the mapped layout, so widget views get the same invariants
as index views (kanban needs a groupable group-by field; calendar needs
a date field + layout). Calendar widget views default to month; a
non-month (DAY/WEEK) layout is rejected at the API level **unless** the
`IS_CALENDAR_WEEK_VIEW_ENABLED` feature flag is enabled for the
workspace — the same flag that gates day/week on index calendars.
- **API.** `upsertViewWidget` (LAYOUTS permission) accepts a nested
`view` settings input (`type`, `mainGroupByFieldMetadataId`,
`shouldHideEmptyGroups`, kanban aggregate/column-width, calendar
layout/fields). Routes through the standard update path, so `viewGroups`
auto-generate from SELECT options exactly like index views. Only widget
view types accepted; only `RECORD_TABLE` widgets can change view
settings.
- **AI tools.** `create-complete-dashboard` + `create_view` now
use/allow the `*_WIDGET` types (previously they created plain `TABLE`
views that leak into index pickers).

## Frontend

**Settings panel.** The **Source** (object) row comes first, since which
layouts are available depends on it. The **Layout** row below is a
working dropdown (Table / Kanban / Calendar); layouts the source object
can't support are **disabled with a hint** ("Needs a Select field" /
"Needs a Date field") rather than hidden. Group-by row (select fields;
searchable) with a **Hide empty groups** toggle while grouped; **Date
field** row replaces Group by while Calendar is active, and — when the
`IS_CALENDAR_WEEK_VIEW_ENABLED` flag is on — a **Calendar view** row
(Day / Week / Month) appears beside it; **Limit** row hidden while
grouped (only the flat virtualized loader enforces it). Kanban keeps its
group-by locked (no `None` option).

**Instant edit-mode preview.** Draft snapshots carry `viewGroups`;
picking a group-by synthesizes them client-side
(`buildDraftViewGroupsForFieldMetadataItem`, mirroring the server's
generation), so grouped tables/boards preview immediately before
dashboard save. On save, `upsertViewWidget` responses hand back the
server-generated groups, which replace the client-generated ones in the
persisted snapshot.

**Renderers.** `RecordTableWidgetRendererContent` branches on the
backing view's layout: `RecordBoardWidget` (wraps the standard
`RecordBoardContainer`) and `RecordCalendarWidget` (mounts the existing
`RecordCalendar`, which renders month / day / week) inside the same
per-widget provider sandbox the table uses.

**Read-only semantics.** Two flags with distinct scopes, each documented
on its state:
- `isRecordBoardViewSettingsReadOnlyComponentState` — locks the board
chrome that edits view settings (add group, column reorder/resize/menu,
aggregates); **card drag still updates records** under object
permissions.
- `isRecordCalendarReadOnlyComponentState` — widget calendars are
read-only by default (no drag, no add-new, no in-calendar layout
switch); cards open the side panel. The one exception, behind
`IS_CALENDAR_WEEK_VIEW_ENABLED`: a **live (non edit-mode) day/week**
widget calendar allows drag-to-reschedule and record creation under
object permissions. Month calendars and edit-mode previews stay
read-only.

**Calendar state componentization.** The calendar module's three
settings move from global atoms to component states keyed on
`RecordCalendarComponentInstanceContext` (same pattern as record-board),
so several calendar widgets and an index-page calendar can coexist
without leaking state. All readers resolve the ambient instance;
calendar unit tests updated.

**Multi-instance fixes that also fix index pages:** record drag states
were written against a different instance than every reader resolves
(now use the ambient instance); the board sticky-header DOM id is
namespaced per board; dragged board cards portal to `document.body`
while dragging so react-grid-layout's transforms can't offset
the clone from the pointer.

## Scope (v1)

- Widget calendars are month-only and read-only by default. With
`IS_CALENDAR_WEEK_VIEW_ENABLED` enabled, day/week layouts become
selectable (UI + API) and live day/week widget calendars support
drag-to-reschedule and record creation under object permissions.
- Widget group-by offers SELECT fields only (server auto-generates
groups from options; widgets have no per-record add-group flow).

## Tests

- Integration: `upsert-view-widget-view-settings.integration-spec.ts` (9
tests — group auto-creation, invalid type/field rejections, non-month
calendar widget rejected while the week/day flag is off and accepted
once it's enabled, combined settings+fields call); pre-existing
`upsert-view-widget` suite (20) green.
- Front: new suites for draft view-group generation and snapshot
clone/build utils; calendar suites componentized; full `twenty-front`
jest, typecheck, oxlint green; `twenty-server` typecheck + lint green.
- Browser-verified end-to-end (real dev server + seeded workspace):
configure → live edit-mode preview → save → reload for all three
layouts; measured drag with pointer inside the card; index-page calendar
re-verified (with the week/day flag enabled).

https://claude.ai/code/session_01E5N87kwwZWhDtEQaP72cMf

packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-builder/validators/services/flat-view-validator.service.ts

@@ -1,7 +1,13 @@
 import { msg, t } from '@lingui/core/macro';
 import { type ALL_METADATA_NAME } from 'twenty-shared/metadata';
-import { FieldMetadataType, RelationType, ViewType } from 'twenty-shared/types';
-import { isDefined } from 'twenty-shared/utils';
+import {
+  FeatureFlagKey,
+  FieldMetadataType,
+  RelationType,
+  ViewCalendarLayout,
+  ViewType,
+} from 'twenty-shared/types';
+import { getViewLayoutFromViewType, isDefined } from 'twenty-shared/utils';
 
 import { findFlatEntityByUniversalIdentifier } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entity-by-universal-identifier.util';
 import { isMorphOrRelationUniversalFlatFieldMetadata } from 'src/engine/metadata-modules/flat-field-metadata/utils/is-morph-or-relation-flat-field-metadata.util';
@@ -23,11 +29,13 @@ export class FlatViewValidatorService {
   private validateCalendarFields({
     flatView,
     flatFieldMetadataMaps,
+    isCalendarWeekViewEnabled,
   }: {
     flatView: UniversalFlatView;
     flatFieldMetadataMaps: AllUniversalFlatEntityMaps['flatFieldMetadataMaps'];
+    isCalendarWeekViewEnabled: boolean;
   }): FlatEntityValidationError[] {
-    if (flatView.type !== ViewType.CALENDAR) {
+    if (getViewLayoutFromViewType(flatView.type) !== ViewType.CALENDAR) {
       return [];
     }
 
@@ -41,6 +49,22 @@ export class FlatViewValidatorService {
       });
     }
 
+    // Widget calendars only allow non-month layouts when the day/week
+    // calendar feature is enabled; while it is off the month grid stays a
+    // data invariant rather than a UI-only convention.
+    if (
+      flatView.type === ViewType.CALENDAR_WIDGET &&
+      !isCalendarWeekViewEnabled &&
+      isDefined(flatView.calendarLayout) &&
+      flatView.calendarLayout !== ViewCalendarLayout.MONTH
+    ) {
+      errors.push({
+        code: ViewExceptionCode.INVALID_VIEW_DATA,
+        message: t`Calendar widget views only support the month layout`,
+        userFriendlyMessage: msg`Calendar widget views only support the month layout`,
+      });
+    }
+
     if (!isDefined(flatView.calendarFieldMetadataUniversalIdentifier)) {
       errors.push({
         code: ViewExceptionCode.INVALID_VIEW_DATA,
@@ -185,6 +209,7 @@ export class FlatViewValidatorService {
       flatViewMaps: optimisticFlatViewMaps,
       flatFieldMetadataMaps,
     },
+    additionalCacheDataMaps: { featureFlagsMap },
   }: FlatEntityUpdateValidationArgs<
     typeof ALL_METADATA_NAME.view
   >): FailedFlatEntityValidation<'view', 'update'> {
@@ -240,8 +265,8 @@ export class FlatViewValidatorService {
     }
 
     const viewBecomesKanban =
-      updatedFlatView.type === ViewType.KANBAN &&
-      existingFlatView.type !== ViewType.KANBAN;
+      getViewLayoutFromViewType(updatedFlatView.type) === ViewType.KANBAN &&
+      getViewLayoutFromViewType(existingFlatView.type) !== ViewType.KANBAN;
 
     if (viewBecomesKanban) {
       if (
@@ -318,6 +343,8 @@ export class FlatViewValidatorService {
       ...this.validateCalendarFields({
         flatView: updatedFlatView,
         flatFieldMetadataMaps,
+        isCalendarWeekViewEnabled:
+          featureFlagsMap[FeatureFlagKey.IS_CALENDAR_WEEK_VIEW_ENABLED],
       }),
     );
 
@@ -392,6 +419,7 @@ export class FlatViewValidatorService {
       flatFieldMetadataMaps,
       flatObjectMetadataMaps,
     },
+    additionalCacheDataMaps: { featureFlagsMap },
   }: UniversalFlatEntityValidationArgs<
     typeof ALL_METADATA_NAME.view
   >): FailedFlatEntityValidation<'view', 'create'> {
@@ -450,7 +478,8 @@ export class FlatViewValidatorService {
       });
     }
 
-    const isKanban = flatViewToValidate.type === ViewType.KANBAN;
+    const isKanban =
+      getViewLayoutFromViewType(flatViewToValidate.type) === ViewType.KANBAN;
 
     if (isKanban) {
       if (
@@ -496,6 +525,8 @@ export class FlatViewValidatorService {
       ...this.validateCalendarFields({
         flatView: flatViewToValidate,
         flatFieldMetadataMaps,
+        isCalendarWeekViewEnabled:
+          featureFlagsMap[FeatureFlagKey.IS_CALENDAR_WEEK_VIEW_ENABLED],
       }),
     );