[1/3] Rename permissionFlag to rolePermissionFlag + add permissionFlag catalog/backfill (#20481)

Split of #20377.

## Summary

This PR separates available permission flags from per-role permission
flag grants.

Previously, `core.permissionFlag` stored the role assignment directly:
`roleId + flag`. This PR renames that legacy grant table to
`core.rolePermissionFlag`, then recreates `core.permissionFlag` as the
catalog of available permission flags.

## What changed

- Rename the existing `core.permissionFlag` grant table to
`core.rolePermissionFlag`.
- Add the new syncable `core.permissionFlag` catalog entity with key,
label, description, icon, permission type, relevance flags, and
custom/standard metadata.
- Add stable `SystemPermissionFlag` universal identifiers for the
built-in `PermissionFlagType` values.
- Seed the standard permission flags for every workspace under the
Twenty standard application.
- Backfill existing role grants:
  - create missing catalog rows for existing grant keys,
  - add `rolePermissionFlag.permissionFlagId`,
- migrate grants from the old string `flag` column to the new catalog
FK,
- replace the old `(flag, roleId)` uniqueness with `(permissionFlagId,
roleId)`.
- Rewire role permission flag caches, permission checks, role DTO
mapping, and `upsertPermissionFlags` to resolve through the catalog.
- Keep the existing public role permission API shape: product/app
surfaces still talk about `permissionFlags` and return `{ id, roleId,
flag }`.
- Update metadata flat-entity machinery, migration builders, validators,
action handlers, snapshots, generated schemas, docs, and app fixtures
for the new `permissionFlag` / `rolePermissionFlag` split.

## Behavior after this PR

- Existing permission flag grants keep working.
- Existing GraphQL role permission flows keep the same public naming.
- Standard permission flags are represented as catalog rows.
- Permission checks now compare grants through catalog universal
identifiers instead of the legacy `flag` column.
- Workspace deletion cleanup now verifies both `permissionFlag` and
`rolePermissionFlag`.

## What is not in this PR

- Public GraphQL CRUD for custom permission flags.
- App manifest support for declaring new custom permission flags.
- Frontend UI for creating or assigning custom permission flags beyond
the existing role permission flow.

---------

Co-authored-by: Weiko <corentin@twenty.com>

packages/twenty-server/src/database/commands/upgrade-version-command/instance-commands.constant.ts

@@ -31,6 +31,10 @@ import { AddToolAndWorkflowActionTriggerSettingsFastInstanceCommand } from 'src/
 import { BackfillApplicationVariableUniversalIdentifierSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-3/2-3-instance-command-slow-1777966965588-backfill-application-variable-universal-identifier';
 import { MigrateToolTriggerSettingsSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-3/2-3-instance-command-slow-1797000002000-migrate-tool-trigger-settings';
 import { AddMetadataToBillingPriceFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-4/2-4-instance-command-fast-1777100000000-add-metadata-to-billing-price';
+import { RenamePermissionFlagToRolePermissionFlagFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-6/2-6-instance-command-fast-1778235340020-rename-permission-flag-to-role-permission-flag';
+import { PermissionFlagSyncableEntityFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-6/2-6-instance-command-fast-1778235340021-permission-flag-syncable-entity';
+import { LinkRolePermissionFlagToPermissionFlagFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-6/2-6-instance-command-fast-1778235340022-link-role-permission-flag-to-permission-flag';
+import { BackfillRolePermissionFlagPermissionFlagIdSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-6/2-6-instance-command-slow-1778235340023-backfill-role-permission-flag-permission-flag-id';
 import { AddEmailGroupChannelTypeFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-4/2-4-instance-command-fast-1778256809018-add-email-group-channel-type';
 import { AddApplicationIdToPublicDomainFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-4/2-4-instance-command-fast-1798000003000-add-application-id-to-public-domain';
 import { AddIsInternalMessagesImportEnabledFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-5/2-5-instance-command-fast-1778525104406-add-is-internal-messages-import-enabled';
@@ -77,6 +81,10 @@ export const INSTANCE_COMMANDS = [
   RemoveUserDefaultAvatarUrlFastInstanceCommand,
   TransformApplicationVariableToSyncableEntityFastInstanceCommand,
   BackfillApplicationVariableUniversalIdentifierSlowInstanceCommand,
+  RenamePermissionFlagToRolePermissionFlagFastInstanceCommand,
+  PermissionFlagSyncableEntityFastInstanceCommand,
+  LinkRolePermissionFlagToPermissionFlagFastInstanceCommand,
+  BackfillRolePermissionFlagPermissionFlagIdSlowInstanceCommand,
   AddEmailGroupChannelTypeFastInstanceCommand,
   AddApplicationIdToPublicDomainFastInstanceCommand,
   AddIsInternalMessagesImportEnabledFastInstanceCommand,