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/service/test_secret_redaction.py

@@ -0,0 +1,88 @@
+from __future__ import annotations
+
+import copy
+
+import pytest
+
+from langbot.pkg.api.http.service.secrets import (
+    contains_secret_placeholder,
+    redact_secrets,
+    restore_secret_placeholders,
+)
+
+
+RAW_CONFIG = {
+    'apiKey': 'api-secret',
+    'dify_apikey': 'dify-secret',
+    'base_url': (
+        'https://service-user:service-password@api.invalid/v1'
+        '?api_key=query-secret&region=sg&X-Amz-Signature=signed-secret'
+    ),
+    'nested': {
+        'headers': {
+            'Authorization': 'Bearer nested-secret',
+            'X-API-Key': 'header-secret',
+            'Accept': 'application/json',
+        },
+        'webhook-url': 'https://hooks.invalid/path?token=secret',
+        'public_key': 'public-material',
+        'tokenizer': 'not-a-secret',
+    },
+    'credentials': {'username': 'service-user', 'password': 'service-password'},
+    'secret_list': ['first-secret', {'value': 'second-secret'}],
+    'empty_secret': '',
+    'enabled': True,
+}
+
+
+def test_recursive_redaction_is_shape_preserving_and_does_not_mutate_source():
+    source = copy.deepcopy(RAW_CONFIG)
+
+    redacted = redact_secrets(source)
+
+    assert redacted['apiKey'] == '***'
+    assert redacted['dify_apikey'] == '***'
+    assert redacted['base_url'] == ('https://***@api.invalid/v1?api_key=***&region=sg&X-Amz-Signature=***')
+    assert redacted['nested']['headers'] == {
+        'Authorization': '***',
+        'X-API-Key': '***',
+        'Accept': 'application/json',
+    }
+    assert redacted['nested']['webhook-url'] == '***'
+    assert redacted['nested']['public_key'] == 'public-material'
+    assert redacted['nested']['tokenizer'] == 'not-a-secret'
+    assert redacted['credentials'] == {'username': '***', 'password': '***'}
+    assert redacted['secret_list'] == ['***', {'value': '***'}]
+    assert redacted['empty_secret'] == ''
+    assert redacted['enabled'] is True
+    assert source == RAW_CONFIG
+
+
+def test_masked_roundtrip_preserves_existing_secrets_and_accepts_replace_and_clear():
+    submitted = redact_secrets(RAW_CONFIG)
+    submitted['enabled'] = False
+    submitted['apiKey'] = 'replacement-secret'
+    submitted['nested']['headers']['X-API-Key'] = ''
+
+    restored = restore_secret_placeholders(submitted, RAW_CONFIG)
+
+    assert restored['apiKey'] == 'replacement-secret'
+    assert restored['dify_apikey'] == 'dify-secret'
+    assert restored['nested']['headers']['Authorization'] == 'Bearer nested-secret'
+    assert restored['nested']['headers']['X-API-Key'] == ''
+    assert restored['nested']['webhook-url'] == RAW_CONFIG['nested']['webhook-url']
+    assert restored['base_url'] == RAW_CONFIG['base_url']
+    assert restored['enabled'] is False
+    assert RAW_CONFIG['apiKey'] == 'api-secret'
+
+
+def test_new_or_extra_masked_secret_fails_closed():
+    assert contains_secret_placeholder({'headers': {'Authorization': '***'}})
+    assert contains_secret_placeholder({'base_url': 'https://***@api.invalid?token=***'})
+    with pytest.raises(ValueError, match='no existing value'):
+        restore_secret_placeholders({'api_key': '***'})
+    with pytest.raises(ValueError, match='no existing value'):
+        restore_secret_placeholders(
+            {'api_keys': ['***', '***']},
+            {'api_keys': ['existing']},
+        )