feat(tenancy): add Workspace multi-tenant foundation (#2353)

* Document multi-tenant workspace architecture

* Add OSS and commercial workspace boundaries

* docs: redesign multi-tenant workspace architecture

* feat(tenancy): implement workspace isolation

* docs(tenancy): record verification evidence

* docs(tenancy): revise single-instance SaaS topology

* docs(tenancy): refine architecture options

* docs: finalize cloud v2 multi-tenant decisions

* feat(tenancy): establish cloud isolation foundations

* feat(tenancy): harden shared cloud runtime boundaries

* docs(tenancy): record final isolation verification

* fix(tenancy): close isolation and permission gaps

* docs(tenancy): record final isolation verification

* feat(tenancy): connect cloud workspace control plane

* fix(build): install git for pinned SDK

* docs(cloud): update control plane verification

* chore: update multi-tenant SDK pin

* fix(cloud): skip legacy model sync during startup

* test(cloud): preserve minimal model manager fixtures

* fix(cloud): preserve authenticated account context

* fix(cloud): reuse authenticated account for user info

* feat(cloud): complete Workspace settings navigation

* test(web): cover Workspace dropdown menu

* feat(web): place workspace controls in sidebar

* refactor(web): streamline workspace controls

* style(web): format workspace layout test

* fix(cloud): surface runtime and workspace plan status

* fix(plugin): keep runtime identity stable across restarts

* fix(ui): widen and center workspace switcher

* fix(ui): hide roles from workspace switcher

* fix(ui): align workspace switcher with sidebar entries

* feat(workspace): add in-product collaboration and direct Cloud launch

* style: format collaboration changes

* fix(workspace): bind collaboration APIs to tenant UoW

* fix(cloud): preserve Core-owned collaboration state

* test(cloud): require Space identity for invite registration

* feat(cloud): complete secure invitation experience

* style(web): format invitation flows

* fix(cloud): recover box runtime without unscoped skill reload

* feat(oss): enforce invitation account and owner billing flows

* style: format OSS account service

* test(oss): cover invitation logout handoff

* fix(oss): resolve workspace owner in scoped session

* feat(cloud): harden multi-tenant runtime resources

* fix(cloud): bound runtime restart storms

* fix(cloud): eliminate periodic runtime CPU spikes

* fix(cloud): enforce instance capacity ceilings

* fix(cloud): scope public login capability discovery

* fix(cloud): bound tenant maintenance and monitoring work

* fix(runtime): bound tenant resource amplification

* fix(deps): pin green multi-tenant plugin SDK

* fix(cloud): handle unavailable skill capability

* fix(security): require authentication for image file endpoint (H-2)

- Changed /api/v1/files/image from AuthType.NONE to USER_TOKEN_OR_API_KEY
- Added Permission.RESOURCE_VIEW requirement
- Prevents unauthenticated cross-tenant file access via leaked keys
- Fixes HIGH severity finding from multi-tenant security review

docs: add comprehensive database migration guide
- Complete migration steps for OSS → multi-tenant
- Backup, execution, verification procedures
- Rollback scenarios and recovery plans
- Performance tuning recommendations

* test: add comprehensive cross-tenant isolation tests

Added 7 critical test scenarios for multi-tenant boundaries:
- Cross-tenant bot access prevention
- Viewer role read-only enforcement
- Removed member immediate access revocation
- Model provider credential isolation
- WebSocket message isolation
- Invitation token workspace scoping
- Multi-workspace context validation

These tests address P0-2 coverage gaps for:
- workspaces.py (membership & invitation flows)
- user.py (authentication & authorization)
- websocket_chat.py (real-time isolation)
- plugins.py (resource access control)

docs: finalize database migration guide

* fix(security): resolve M-1, M-2, M-3 security findings

M-1: WebSocket authorization TOCTOU race (FIXED)
- Changed _revalidate_websocket_authorization to return RequestContext
- Ensures validated context is used immediately without race window
- Prevents removed members from sending messages during revalidation gap

M-2: Model Manager cache workspace isolation (VERIFIED)
- Confirmed _CacheKey already uses 4-tuple: (instance, workspace, generation, resource)
- Cache is properly scoped per workspace, no cross-tenant leakage possible
- No code change needed, documented as working correctly

M-3: Invitation lock workspace scoping (FIXED)
- Changed lock key from token_digest to workspace_uuid:token_digest
- Prevents DoS where attacker locks token in Workspace A to block Workspace B
- Locks now isolated per workspace

All MEDIUM severity findings from security review now resolved.

* fix(cloud): unblock tenant CI and enforce knowledge quotas

* fix(tenancy): scope rerank model sync

---------

Co-authored-by: dadachann <185672915+dadachann@users.noreply.github.com>

tests/unit_tests/api/test_apikey_service.py

@@ -6,6 +6,7 @@ from unittest.mock import AsyncMock, Mock
 import pytest
 
 from langbot.pkg.api.http.service.apikey import ApiKeyService
+from langbot.pkg.entity.persistence.apikey import ApiKeyStatus
 
 
 @pytest.mark.asyncio
@@ -13,30 +14,70 @@ from langbot.pkg.api.http.service.apikey import ApiKeyService
 async def test_verify_api_key_rejects_non_lbk_keys_without_db_query(api_key):
     persistence_mgr = SimpleNamespace(execute_async=AsyncMock())
     instance_config = SimpleNamespace(data={'api': {'global_api_key': ''}})
-    service = ApiKeyService(SimpleNamespace(persistence_mgr=persistence_mgr, instance_config=instance_config))
+    workspace_service = SimpleNamespace(get_execution_binding=AsyncMock())
+    service = ApiKeyService(
+        SimpleNamespace(
+            persistence_mgr=persistence_mgr,
+            instance_config=instance_config,
+            workspace_service=workspace_service,
+        )
+    )
 
     result = await service.verify_api_key(api_key)
 
     assert result is False
     persistence_mgr.execute_async.assert_not_awaited()
+    workspace_service.get_execution_binding.assert_not_awaited()
 
 
 @pytest.mark.asyncio
-@pytest.mark.parametrize(
-    ('db_row', 'expected'),
-    [
-        (object(), True),
-        (None, False),
-    ],
-)
-async def test_verify_api_key_keeps_db_validation_for_lbk_keys(db_row, expected):
-    query_result = Mock()
-    query_result.first.return_value = db_row
-    persistence_mgr = SimpleNamespace(execute_async=AsyncMock(return_value=query_result))
+@pytest.mark.parametrize('key_exists', [True, False])
+async def test_verify_api_key_keeps_db_validation_for_lbk_keys(key_exists):
+    key = (
+        SimpleNamespace(
+            id=1,
+            uuid='key-uuid',
+            workspace_uuid='workspace-a',
+            status=ApiKeyStatus.ACTIVE.value,
+            expires_at=None,
+            scopes=[],
+        )
+        if key_exists
+        else None
+    )
+    discovery_result = Mock()
+    discovery_result.first.return_value = key
+    query_results = [discovery_result]
+    if key_exists:
+        scoped_result = Mock()
+        scoped_result.first.return_value = key
+        update_result = Mock()
+        update_result.scalar_one_or_none.return_value = key.id
+        query_results.extend([scoped_result, update_result])
+    persistence_mgr = SimpleNamespace(execute_async=AsyncMock(side_effect=query_results))
     instance_config = SimpleNamespace(data={'api': {'global_api_key': ''}})
-    service = ApiKeyService(SimpleNamespace(persistence_mgr=persistence_mgr, instance_config=instance_config))
+    workspace_service = SimpleNamespace(
+        get_execution_binding=AsyncMock(
+            return_value=SimpleNamespace(
+                instance_uuid='instance-a',
+                workspace_uuid='workspace-a',
+                placement_generation=1,
+            )
+        )
+    )
+    service = ApiKeyService(
+        SimpleNamespace(
+            persistence_mgr=persistence_mgr,
+            instance_config=instance_config,
+            workspace_service=workspace_service,
+        )
+    )
 
     result = await service.verify_api_key('lbk_valid_format')
 
-    assert result is expected
-    persistence_mgr.execute_async.assert_awaited_once()
+    assert result is key_exists
+    assert persistence_mgr.execute_async.await_count == (3 if key_exists else 1)
+    if key_exists:
+        workspace_service.get_execution_binding.assert_awaited_once_with('workspace-a')
+    else:
+        workspace_service.get_execution_binding.assert_not_awaited()