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>

src/langbot/pkg/api/http/service/space.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from collections import OrderedDict
+
 from langbot.pkg.utils import httpclient
 import typing
 import datetime
@@ -11,6 +13,10 @@ from ....entity.persistence import user
 from ....entity.dto.space_model import SpaceModel
 
 
+_CREDITS_CACHE_TTL_SECONDS = 60
+_CREDITS_CACHE_MAX_ENTRIES = 4096
+
+
 class SpaceService:
     """Service for interacting with LangBot Space API"""
 
@@ -19,7 +25,24 @@ class SpaceService:
 
     def __init__(self, ap: app.Application) -> None:
         self.ap = ap
-        self._credits_cache = {}
+        self._credits_cache = OrderedDict()
+
+    def _ordered_credits_cache(
+        self,
+    ) -> OrderedDict[str, tuple[int, float]]:
+        if not isinstance(self._credits_cache, OrderedDict):
+            # Preserve compatibility with tests and callers that seed the cache.
+            self._credits_cache = OrderedDict(self._credits_cache)
+        return self._credits_cache
+
+    def _prune_credits_cache(self, now: float) -> None:
+        cache = self._ordered_credits_cache()
+        while cache:
+            email = next(iter(cache))
+            _, cached_at = cache[email]
+            if now - cached_at < _CREDITS_CACHE_TTL_SECONDS:
+                break
+            cache.pop(email, None)
 
     def _get_space_config(self) -> typing.Dict[str, str]:
         """Get Space configuration from config file"""
@@ -85,12 +108,14 @@ class SpaceService:
 
     def get_oauth_authorize_url(self, redirect_uri: str, state: str = '') -> str:
         """Get the Space OAuth authorization URL for redirect"""
+        from urllib.parse import urlencode
+
         space_config = self._get_space_config()
         authorize_url = space_config['oauth_authorize_url']
-        params = f'redirect_uri={redirect_uri}'
+        params = {'redirect_uri': redirect_uri}
         if state:
-            params += f'&state={state}'
-        return f'{authorize_url}?{params}'
+            params['state'] = state
+        return f'{authorize_url}?{urlencode(params)}'
 
     async def exchange_oauth_code(self, code: str) -> typing.Dict:
         """Exchange OAuth authorization code for tokens"""
@@ -105,8 +130,9 @@ class SpaceService:
             json={'code': code, 'instance_id': constants.instance_id},
         ) as response:
             if response.status != 200:
-                raise ValueError(f'Failed to exchange OAuth code: {await response.text()}')
-            data = await response.json()
+                error = await httpclient.read_text_limited(response)
+                raise ValueError(f'Failed to exchange OAuth code: {error}')
+            data = await httpclient.read_json_limited(response)
             if data.get('code') != 0:
                 raise ValueError(f'Failed to exchange OAuth code: {data.get("msg")}')
             return data.get('data', {})
@@ -121,8 +147,9 @@ class SpaceService:
             f'{space_url}/api/v1/accounts/token/refresh', json={'refresh_token': refresh_token}
         ) as response:
             if response.status != 200:
-                raise ValueError(f'Failed to refresh token: {await response.text()}')
-            data = await response.json()
+                error = await httpclient.read_text_limited(response)
+                raise ValueError(f'Failed to refresh token: {error}')
+            data = await httpclient.read_json_limited(response)
             if data.get('code') != 0:
                 raise ValueError(f'Failed to refresh token: {data.get("msg")}')
             return data.get('data', {})
@@ -137,8 +164,9 @@ class SpaceService:
             f'{space_url}/api/v1/accounts/me', headers={'Authorization': f'Bearer {access_token}'}
         ) as response:
             if response.status != 200:
-                raise ValueError(f'Failed to get user info: {await response.text()}')
-            data = await response.json()
+                error = await httpclient.read_text_limited(response)
+                raise ValueError(f'Failed to get user info: {error}')
+            data = await httpclient.read_json_limited(response)
             if data.get('code') != 0:
                 raise ValueError(f'Failed to get user info: {data.get("msg")}')
             return data.get('data', {})
@@ -154,11 +182,13 @@ class SpaceService:
 
     async def get_credits(self, user_email: str, force_refresh: bool = False) -> int | None:
         """Get Space credits for user with caching (60s TTL)"""
-        cache_ttl = 60
+        now = time.time()
+        cached_fallback = self._credits_cache.get(user_email)
+        self._prune_credits_cache(now)
 
         if not force_refresh and user_email in self._credits_cache:
             credits, ts = self._credits_cache[user_email]
-            if time.time() - ts < cache_ttl:
+            if now - ts < _CREDITS_CACHE_TTL_SECONDS:
                 return credits
 
         try:
@@ -167,10 +197,14 @@ class SpaceService:
                 return None
             credits = info.get('credits')
             if credits is not None:
-                self._credits_cache[user_email] = (credits, time.time())
+                cache = self._ordered_credits_cache()
+                cache.pop(user_email, None)
+                if len(cache) >= _CREDITS_CACHE_MAX_ENTRIES:
+                    cache.popitem(last=False)
+                cache[user_email] = (credits, time.time())
             return credits
         except Exception:
-            return self._credits_cache.get(user_email, (None, 0))[0]
+            return cached_fallback[0] if cached_fallback is not None else None
 
     async def get_models(self) -> typing.List[SpaceModel]:
         """Get models from Space"""
@@ -181,8 +215,9 @@ class SpaceService:
         session = httpclient.get_session()
         async with session.get(f'{space_url}/api/v1/models', params={'page_size': 100}) as response:
             if response.status != 200:
-                raise ValueError(f'Failed to get models: {await response.text()}')
-            data = await response.json()
+                error = await httpclient.read_text_limited(response)
+                raise ValueError(f'Failed to get models: {error}')
+            data = await httpclient.read_json_limited(response)
             if data.get('code') != 0:
                 raise ValueError(f'Failed to get models: {data.get("msg")}')
             models_data = data.get('data', {}).get('models', [])