fix(cloud): track workspace membership provenance

src/langbot/pkg/cloud/directory_projection.py

@@ -15,6 +15,7 @@ from ..entity.persistence.cloud_directory import DirectoryProjectionInbox, Direc
 from ..entity.persistence.user import AccountSource, AccountStatus, User
 from ..entity.persistence.workspace import (
     MembershipRole,
+    MembershipSource,
     MembershipStatus,
     Workspace,
     WorkspaceExecutionSource,
@@ -865,12 +866,6 @@ class DirectoryProjectionService:
                 )
             ).all()
         }
-        existing_account_sources: dict[str, str] = {}
-        if existing:
-            existing_account_sources = {
-                account.uuid: account.source
-                for account in (await session.scalars(sqlalchemy.select(User).where(User.uuid.in_(existing)))).all()
-            }
         included_accounts: set[str] = set()
         for member in candidate.members:
             included_accounts.add(member.account_uuid)
@@ -892,18 +887,15 @@ class DirectoryProjectionService:
                         account_uuid=member.account_uuid,
                         role=role,
                         status=status,
+                        source=MembershipSource.CLOUD_PROJECTION.value,
                         joined_at=joined_at,
                         projection_revision=member.projection_revision,
                     )
                 )
                 continue
-            if (
-                membership.projection_revision == 0
-                and existing_account_sources.get(member.account_uuid) != AccountSource.CLOUD_PROJECTION.value
-            ):
-                # Keep genuinely local collaboration state. Historical Cloud
-                # memberships also used revision zero; once Space includes the
-                # account in its authoritative directory, adopt that row.
+            if membership.source != MembershipSource.CLOUD_PROJECTION.value:
+                # Core-owned collaboration state is never adopted based on
+                # account provenance, revision, or matching account identity.
                 continue
             if membership.uuid != member.membership_uuid:
                 raise DirectoryProjectionUnavailableError('Directory membership UUID changed for one account')
@@ -915,12 +907,12 @@ class DirectoryProjectionService:
                 raise DirectoryProjectionUnavailableError('Directory membership revision has conflicting contents')
             membership.role = role
             membership.status = status
+            membership.source = MembershipSource.CLOUD_PROJECTION.value
             membership.joined_at = joined_at
             membership.projection_revision = member.projection_revision
 
         for account_uuid, membership in existing.items():
-            space_owned = existing_account_sources.get(account_uuid) == AccountSource.CLOUD_PROJECTION.value
-            if account_uuid not in included_accounts and (membership.projection_revision != 0 or space_owned):
+            if account_uuid not in included_accounts and membership.source == MembershipSource.CLOUD_PROJECTION.value:
                 membership.status = MembershipStatus.REMOVED.value
                 membership.projection_revision = max(
                     int(membership.projection_revision),

src/langbot/pkg/entity/persistence/workspace.py

@@ -40,6 +40,11 @@ class MembershipStatus(enum.StrEnum):
     REMOVED = 'removed'
 
 
+class MembershipSource(enum.StrEnum):
+    LOCAL = 'local'
+    CLOUD_PROJECTION = 'cloud_projection'
+
+
 class InvitationStatus(enum.StrEnum):
     PENDING = 'pending'
     ACCEPTED = 'accepted'
@@ -151,6 +156,11 @@ class WorkspaceMembership(Base):
         nullable=True,
     )
     joined_at = sqlalchemy.Column(sqlalchemy.DateTime, nullable=True)
+    source = sqlalchemy.Column(
+        sqlalchemy.String(32),
+        nullable=False,
+        server_default=MembershipSource.LOCAL.value,
+    )
     projection_revision = sqlalchemy.Column(sqlalchemy.BigInteger, nullable=False, server_default='0')
     created_at = sqlalchemy.Column(sqlalchemy.DateTime, nullable=False, server_default=sqlalchemy.func.now())
     updated_at = sqlalchemy.Column(
@@ -178,6 +188,10 @@ class WorkspaceMembership(Base):
             "status IN ('active', 'disabled', 'removed')",
             name='ck_workspace_memberships_status',
         ),
+        sqlalchemy.CheckConstraint(
+            "source IN ('local', 'cloud_projection')",
+            name='ck_workspace_memberships_source',
+        ),
     )
 
 

src/langbot/pkg/persistence/alembic/versions/0020_workspace_membership_source.py

@@ -0,0 +1,49 @@
+"""add explicit Workspace membership source
+
+Revision ID: 0020_membership_source
+Revises: 001a_pgvector_dimension_3072
+Create Date: 2026-08-06
+"""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = '0020_membership_source'
+down_revision = '001a_pgvector_dimension_3072'
+branch_labels = None
+depends_on = None
+
+_CONSTRAINT_NAME = 'ck_workspace_memberships_source'
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+    inspector = sa.inspect(conn)
+    if 'workspace_memberships' not in inspector.get_table_names():
+        return
+    if 'source' in {column['name'] for column in inspector.get_columns('workspace_memberships')}:
+        return
+
+    # No durable historical field distinguishes Directory-created revision-zero
+    # rows from Core invitations. Protect every existing row; production can
+    # reclassify separately after UUIDs have been verified against Space.
+    with op.batch_alter_table('workspace_memberships') as batch_op:
+        batch_op.add_column(sa.Column('source', sa.String(length=32), nullable=False, server_default='local'))
+        batch_op.create_check_constraint(
+            _CONSTRAINT_NAME,
+            "source IN ('local', 'cloud_projection')",
+        )
+
+
+def downgrade() -> None:
+    conn = op.get_bind()
+    inspector = sa.inspect(conn)
+    if 'workspace_memberships' not in inspector.get_table_names():
+        return
+    if 'source' not in {column['name'] for column in inspector.get_columns('workspace_memberships')}:
+        return
+    with op.batch_alter_table('workspace_memberships') as batch_op:
+        batch_op.drop_constraint(_CONSTRAINT_NAME, type_='check')
+        batch_op.drop_column('source')

src/langbot/pkg/workspace/collaboration.py

@@ -17,6 +17,7 @@ from ..entity.persistence.user import AccountStatus, User
 from ..entity.persistence.workspace import (
     InvitationStatus,
     MembershipRole,
+    MembershipSource,
     MembershipStatus,
     Workspace,
     WorkspaceInvitation,
@@ -483,6 +484,7 @@ class WorkspaceCollaborationService:
                     account_uuid=account_uuid,
                     role=invitation.role,
                     status=MembershipStatus.ACTIVE.value,
+                    source=MembershipSource.LOCAL.value,
                     invited_by_account_uuid=invitation.created_by_account_uuid,
                     joined_at=now,
                     projection_revision=0,
@@ -491,6 +493,7 @@ class WorkspaceCollaborationService:
             elif membership.status != MembershipStatus.ACTIVE.value:
                 membership.role = invitation.role
                 membership.status = MembershipStatus.ACTIVE.value
+                membership.source = MembershipSource.LOCAL.value
                 membership.invited_by_account_uuid = invitation.created_by_account_uuid
                 membership.joined_at = now
 

src/langbot/pkg/workspace/service.py

@@ -11,6 +11,7 @@ from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
 
 from ..entity.persistence.workspace import (
     MembershipRole,
+    MembershipSource,
     MembershipStatus,
     Workspace,
     WorkspaceExecutionSource,
@@ -451,6 +452,7 @@ class WorkspaceService:
                 account_uuid=account_uuid,
                 role=MembershipRole.OWNER.value,
                 status=MembershipStatus.ACTIVE.value,
+                source=MembershipSource.LOCAL.value,
                 joined_at=joined_at,
                 projection_revision=0,
             )
@@ -458,6 +460,7 @@ class WorkspaceService:
         else:
             membership.role = MembershipRole.OWNER.value
             membership.status = MembershipStatus.ACTIVE.value
+            membership.source = MembershipSource.LOCAL.value
             membership.joined_at = membership.joined_at or joined_at
 
         if workspace.created_by_account_uuid is None: