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/platform/sources/aiocqhttp.py

@@ -23,6 +23,7 @@ _GROUP_NAME_LOOKUP_TIMEOUT_SECONDS = 2
 _GROUP_MEMBER_INFO_CACHE_TTL_SECONDS = 86400
 _GROUP_MEMBER_INFO_NEGATIVE_CACHE_TTL_SECONDS = 600
 _GROUP_MEMBER_INFO_LOOKUP_TIMEOUT_SECONDS = 2
+_LOOKUP_CACHE_MAX = 4096
 
 
 def _normalize_base64_payload(value: str) -> str:
@@ -372,6 +373,31 @@ class AiocqhttpEventConverter(abstract_platform_adapter.AbstractEventConverter):
             tuple[typing.Union[int, str], typing.Union[int, str]], tuple[dict, float]
         ] = {}
         self._group_member_info_negative_cache: dict[tuple[typing.Union[int, str], typing.Union[int, str]], float] = {}
+        self._last_cache_cleanup = 0.0
+
+    def _prune_caches(self, now: float) -> None:
+        caches = (
+            self._group_name_cache,
+            self._group_name_negative_cache,
+            self._group_member_info_cache,
+            self._group_member_info_negative_cache,
+        )
+        if now - self._last_cache_cleanup < 60 and all(len(cache) <= _LOOKUP_CACHE_MAX for cache in caches):
+            return
+        self._last_cache_cleanup = now
+        for cache in caches:
+            for key, value in tuple(cache.items()):
+                expires_at = value[1] if isinstance(value, tuple) else value
+                if expires_at <= now:
+                    cache.pop(key, None)
+            while len(cache) > _LOOKUP_CACHE_MAX:
+                cache.pop(next(iter(cache)), None)
+
+    def clear(self) -> None:
+        self._group_name_cache.clear()
+        self._group_name_negative_cache.clear()
+        self._group_member_info_cache.clear()
+        self._group_member_info_negative_cache.clear()
 
     @staticmethod
     async def yiri2target(event: platform_events.MessageEvent, bot_account_id: int):
@@ -379,6 +405,7 @@ class AiocqhttpEventConverter(abstract_platform_adapter.AbstractEventConverter):
 
     async def _get_group_name(self, group_id: typing.Union[int, str], bot=None) -> str:
         now = time.monotonic()
+        self._prune_caches(now)
         if group_id in self._group_name_cache:
             group_name, expires_at = self._group_name_cache[group_id]
             if expires_at > now:
@@ -414,6 +441,7 @@ class AiocqhttpEventConverter(abstract_platform_adapter.AbstractEventConverter):
         bot=None,
     ) -> dict:
         now = time.monotonic()
+        self._prune_caches(now)
         cache_key = (group_id, user_id)
         if cache_key in self._group_member_info_cache:
             member_info, expires_at = self._group_member_info_cache[cache_key]
@@ -532,6 +560,8 @@ class AiocqhttpAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter)
                 return
 
         self.on_websocket_connection_event_cache.append(event)
+        if len(self.on_websocket_connection_event_cache) > 100:
+            self.on_websocket_connection_event_cache.pop(0)
         await self.logger.info(f'WebSocket connection established, bot id: {event.self_id}')
 
     async def send_message(self, target_type: str, target_id: str, message: platform_message.MessageChain):
@@ -697,4 +727,6 @@ class AiocqhttpAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter)
     async def kill(self) -> bool:
         # Current issue: existing connection will not be closed
         # self.should_shutdown = True
+        self.on_websocket_connection_event_cache.clear()
+        self.event_converter.clear()
         return False