Split inactive profile state

Replace the binary profile ACTIVE/INACTIVE model with PENDING, ACTIVE,
and DEACTIVATED so invited-but-not-yet-activated members remain
assignable to assets, data, and risks instead of being treated like
deactivated users.

Add activated_at/deactivated_at timestamps and Mark* lifecycle helpers,
and update every transition (create, invite/re-invite, activation,
archive, SCIM, SAML, sessions, compliance-portal grant) to the new
states. Expose a multi-state states[] filter across coredata, GraphQL,
MCP, and the console owner pickers, which now request ACTIVE and
PENDING members.

A migration renames the membership_state enum, classifies existing
inactive profiles as PENDING from recent invitation activity, and
backfills the new timestamp columns.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/iam/auth_service.go

@@ -179,9 +179,8 @@ func (s *AuthService) ActivateAccount(
 				return NewUserManagedBySCIMError(profile.ID)
 			}
 
-			if profile.State == coredata.ProfileStateInactive {
-				profile.State = coredata.ProfileStateActive
-				profile.UpdatedAt = now
+			if profile.State == coredata.ProfileStatePending {
+				profile.MarkActive(now)
 
 				if err := profile.Update(ctx, tx, scope); err != nil {
 					return fmt.Errorf("cannot update user: %w", err)