Deprecate workspace metadataVersion and stop consuming it in the frontend (#23189)

## Context

Follow-up to #23164. Now that the metadata GraphQL response cache and
the workspace SDL cache are keyed on flat-map hashes,
`workspace.metadataVersion` no longer drives any cache invalidation.
This PR is the next stage of retiring it: the frontend stops consuming
the field entirely, and the public GraphQL field is marked deprecated so
external API consumers get a migration signal.

## What changed

**Frontend stops consuming `metadataVersion`:**
- `userQueryFragment.ts` no longer selects the field.
- `currentWorkspaceState.ts` drops it from the workspace `Pick`.
- `apollo.factory.ts` no longer attaches the `X-Schema-Version` request
header.

Dropping the header retires the "your workspace has been updated, please
refresh the page" error rewrite on the server (it only fired when the
header was present, and only on requests that had already failed
validation). Metadata staleness detection is unaffected: the frontend
has been running on collection hashes plus SSE since the
minimal-metadata work, so that path stays intact. Stale clients now
surface a raw validation error instead of the friendly message, which we
consider an acceptable trade for deleting the mechanism.

**Server marks the field deprecated:**
- `workspace.entity.ts`: `@Field({ deprecationReason: 'No longer used
for metadata cache invalidation, will be removed' })`.

**Regenerated (CI-enforced surfaces):**
`twenty-front/src/generated-metadata`, and `twenty-client-sdk`'s
generated schema, which now carries `@deprecated(reason: ...)`. The
`admin` codegen config produced no changes.
`packages/twenty-sdk/generated` is intentionally untouched: no in-repo
command produces it, CI does not drift-check it, and its committed
snapshot lags the live schema, so regenerating it here would pull
unrelated schema drift into this PR; it will pick up the directive on
its next routine refresh.

## Deployment notes

- No ordering constraint with #23164: removing a field selection and a
request header is backward compatible against any server, and old
frontend bundles keep working during the rollout because the field still
exists and the server-side header check is still in place. Same release
is fine.
- The follow-up server cleanup (removing the `X-Schema-Version` check in
`use-graphql-error-handler.hook.ts`, the per-request `metadataVersion`
reads and seed in `middleware.service.ts`/`jwt-auth.guard.ts`, and the
REST heal block) must wait until the release containing this PR has
shipped, since a deployed frontend still selecting the field would break
`GetCurrentUser` if the field were removed first.

After that cleanup, the only remaining `metadataVersion` consumers are
the five pinned upgrade commands (2.8 through 2.20), which hold the
column and `WorkspaceMetadataVersionService` until that upgrade window
closes; the physical column drop then follows the two-phase pattern used
for `gridPosition`.

## Validation

- Server and frontend typecheck, lint, and format pass; the apollo
factory test suite passes unchanged (it fixtures the field but never
asserted the header).
- Live introspection against a server running this branch returns
`isDeprecated: true` with the reason on `Workspace.metadataVersion`.
- CI's pending-codegen check covers the regenerated surfaces
(`data`/`metadata`/`admin` configs and
`twenty-client-sdk:generate-metadata-client`).

<!-- This is an auto-generated description by cubic. -->
<a
href="https://cubic.dev/pr/twentyhq/twenty/pull/23189?utm_source=github"
target="_blank" rel="noopener noreferrer"
data-no-image-dialog="true"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://www.cubic.dev/buttons/review-in-cubic-dark.svg"><source
media="(prefers-color-scheme: light)"
srcset="https://www.cubic.dev/buttons/review-in-cubic-light.svg"><img
alt="Review in cubic"
src="https://www.cubic.dev/buttons/review-in-cubic-dark.svg"></picture></a>
<!-- End of auto-generated description by cubic. -->

packages/twenty-client-sdk/src/metadata/generated/schema.graphql

@@ -869,7 +869,7 @@ type Workspace {
   viewFilterGroups: [ViewFilterGroup!]
   viewGroups: [ViewGroup!]
   viewSorts: [ViewSort!]
-  metadataVersion: Float!
+  metadataVersion: Float! @deprecated(reason: "No longer used for metadata cache invalidation, will be removed")
   databaseSchema: String
   subdomain: String!
   customDomain: String

packages/twenty-client-sdk/src/metadata/generated/schema.ts

@@ -611,6 +611,7 @@ export interface Workspace {
     viewFilterGroups?: ViewFilterGroup[]
     viewGroups?: ViewGroup[]
     viewSorts?: ViewSort[]
+    /** @deprecated No longer used for metadata cache invalidation, will be removed */
     metadataVersion: Scalars['Float']
     databaseSchema?: Scalars['String']
     subdomain: Scalars['String']
@@ -3703,6 +3704,7 @@ export interface WorkspaceGenqlSelection{
     viewFilterGroups?: ViewFilterGroupGenqlSelection
     viewGroups?: ViewGroupGenqlSelection
     viewSorts?: ViewSortGenqlSelection
+    /** @deprecated No longer used for metadata cache invalidation, will be removed */
     metadataVersion?: boolean | number
     databaseSchema?: boolean | number
     subdomain?: boolean | number

packages/twenty-front/src/modules/apollo/services/apollo.factory.ts

@@ -147,9 +147,6 @@ export class ApolloFactory implements ApolloManager {
             ...optionHeaders,
             authorization: token ? `Bearer ${token}` : '',
             'x-locale': locale,
-            ...(isDefined(this.currentWorkspace?.metadataVersion) && {
-              'X-Schema-Version': `${this.currentWorkspace.metadataVersion}`,
-            }),
             ...(this.appVersion && { 'X-App-Version': this.appVersion }),
           },
         };

packages/twenty-front/src/modules/auth/states/currentWorkspaceState.ts

@@ -33,7 +33,6 @@ export type CurrentWorkspace = Pick<
   | 'subdomain'
   | 'customDomain'
   | 'workspaceUrls'
-  | 'metadataVersion'
   | 'isTwoFactorAuthenticationEnforced'
   | 'trashRetentionDays'
   | 'eventLogRetentionDays'

packages/twenty-front/src/modules/users/graphql/fragments/userQueryFragment.ts

@@ -81,7 +81,6 @@ export const USER_QUERY_FRAGMENT = gql`
         key
         value
       }
-      metadataVersion
       currentBillingSubscription {
         ...CurrentBillingSubscriptionFragment
       }

packages/twenty-server/src/engine/core-modules/workspace/workspace.entity.ts

@@ -246,7 +246,10 @@ export class WorkspaceEntity {
   @OneToMany(() => ViewSortEntity, (viewSort) => viewSort.workspace)
   viewSorts: Relation<ViewSortEntity[]>;
 
-  @Field()
+  @Field({
+    deprecationReason:
+      'No longer used for metadata cache invalidation, will be removed',
+  })
   @Column({ default: 1 })
   metadataVersion: number;