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/matrix.py

@@ -5,6 +5,8 @@ import asyncio
 import traceback
 import base64
 import json
+import os
+from urllib.parse import urlparse
 
 import nio
 
@@ -16,6 +18,58 @@ import langbot_plugin.api.entities.builtin.platform.entities as platform_entitie
 import langbot_plugin.api.definition.abstract.platform.event_logger as abstract_platform_logger
 
 
+_MAX_MATRIX_MEDIA_BYTES = 10 * 1024 * 1024
+
+
+def _decode_matrix_base64_limited(value: str) -> bytes:
+    if ';base64,' in value:
+        value = value.split(';base64,', 1)[1]
+    max_encoded_bytes = 4 * ((_MAX_MATRIX_MEDIA_BYTES + 2) // 3)
+    if len(value) > max_encoded_bytes:
+        raise ValueError('Matrix media exceeds the size limit')
+    decoded = base64.b64decode(value)
+    if len(decoded) > _MAX_MATRIX_MEDIA_BYTES:
+        raise ValueError('Matrix media exceeds the size limit')
+    return decoded
+
+
+def _read_matrix_file_limited(path: str) -> bytes:
+    if os.path.getsize(path) > _MAX_MATRIX_MEDIA_BYTES:
+        raise ValueError('Matrix media exceeds the size limit')
+    with open(path, 'rb') as file:
+        body = file.read(_MAX_MATRIX_MEDIA_BYTES + 1)
+    if len(body) > _MAX_MATRIX_MEDIA_BYTES:
+        raise ValueError('Matrix media exceeds the size limit')
+    return body
+
+
+async def _download_matrix_media_limited(
+    client: nio.AsyncClient,
+    mxc_url: str,
+) -> tuple[bytes, str]:
+    parsed = urlparse(mxc_url)
+    if parsed.scheme != 'mxc' or not parsed.netloc or not parsed.path.strip('/'):
+        raise ValueError('Invalid Matrix media URL')
+    method, path = nio.Api.download(
+        parsed.netloc,
+        parsed.path.replace('/', ''),
+        access_token=None,
+    )
+    headers = {}
+    if client.access_token:
+        headers['Authorization'] = f'Bearer {client.access_token}'
+    response = await client.send(method, path, headers=headers, timeout=30)
+    try:
+        response.raise_for_status()
+        body = await httpclient.read_limited(
+            response,
+            max_bytes=_MAX_MATRIX_MEDIA_BYTES,
+        )
+        return body, response.headers.get('Content-Type', 'application/octet-stream')
+    finally:
+        response.release()
+
+
 class MatrixMessageConverter(abstract_platform_adapter.AbstractMessageConverter):
     @staticmethod
     async def yiri2target(message_chain: platform_message.MessageChain, client: nio.AsyncClient) -> list[dict]:
@@ -26,17 +80,22 @@ class MatrixMessageConverter(abstract_platform_adapter.AbstractMessageConverter)
             elif isinstance(component, platform_message.Image):
                 image_bytes = None
                 if component.base64:
-                    b64_data = component.base64
-                    if ';base64,' in b64_data:
-                        b64_data = b64_data.split(';base64,', 1)[1]
-                    image_bytes = base64.b64decode(b64_data)
+                    image_bytes = await asyncio.to_thread(
+                        _decode_matrix_base64_limited,
+                        component.base64,
+                    )
                 elif component.url:
                     session = httpclient.get_session()
                     async with session.get(component.url) as response:
-                        image_bytes = await response.read()
+                        image_bytes = await httpclient.read_limited(
+                            response,
+                            max_bytes=_MAX_MATRIX_MEDIA_BYTES,
+                        )
                 elif component.path:
-                    with open(component.path, 'rb') as f:
-                        image_bytes = f.read()
+                    image_bytes = await asyncio.to_thread(
+                        _read_matrix_file_limited,
+                        str(component.path),
+                    )
                 if image_bytes:
                     resp = await client.upload(image_bytes, content_type='image/png')
                     if isinstance(resp, nio.UploadResponse):
@@ -44,17 +103,22 @@ class MatrixMessageConverter(abstract_platform_adapter.AbstractMessageConverter)
             elif isinstance(component, platform_message.File):
                 file_bytes = None
                 if component.base64:
-                    b64_data = component.base64
-                    if ';base64,' in b64_data:
-                        b64_data = b64_data.split(';base64,', 1)[1]
-                    file_bytes = base64.b64decode(b64_data)
+                    file_bytes = await asyncio.to_thread(
+                        _decode_matrix_base64_limited,
+                        component.base64,
+                    )
                 elif component.url:
                     session = httpclient.get_session()
                     async with session.get(component.url) as response:
-                        file_bytes = await response.read()
+                        file_bytes = await httpclient.read_limited(
+                            response,
+                            max_bytes=_MAX_MATRIX_MEDIA_BYTES,
+                        )
                 elif component.path:
-                    with open(component.path, 'rb') as f:
-                        file_bytes = f.read()
+                    file_bytes = await asyncio.to_thread(
+                        _read_matrix_file_limited,
+                        str(component.path),
+                    )
                 if file_bytes:
                     file_name = getattr(component, 'name', None) or 'file'
                     resp = await client.upload(file_bytes, content_type='application/octet-stream', filename=file_name)
@@ -86,11 +150,12 @@ class MatrixMessageConverter(abstract_platform_adapter.AbstractMessageConverter)
         elif isinstance(event, nio.RoomMessageImage):
             mxc_url = event.url
             if mxc_url:
-                resp = await client.download(mxc_url)
-                if isinstance(resp, nio.DownloadResponse):
-                    b64 = base64.b64encode(resp.body).decode('utf-8')
-                    content_type = resp.content_type or 'image/png'
-                    message_components.append(platform_message.Image(base64=f'data:{content_type};base64,{b64}'))
+                body, content_type = await _download_matrix_media_limited(
+                    client,
+                    mxc_url,
+                )
+                b64 = (await asyncio.to_thread(base64.b64encode, body)).decode('utf-8')
+                message_components.append(platform_message.Image(base64=f'data:{content_type};base64,{b64}'))
             if event.body:
                 message_components.append(platform_message.Plain(text=event.body))
 
@@ -431,14 +496,15 @@ class MatrixAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter):
                 if not mxc_url:
                     return
                 try:
-                    resp = await self.client.download(mxc_url)
-                    if isinstance(resp, nio.DownloadResponse):
-                        b64 = base64.b64encode(resp.body).decode('utf-8')
-                        content_type = resp.content_type or 'image/png'
-                        await self.logger.info(
-                            f'[{_b.user_id}] Bridge 发送了二维码，请扫码登录:',
-                            images=[platform_message.Image(base64=f'data:{content_type};base64,{b64}')],
-                        )
+                    body, content_type = await _download_matrix_media_limited(
+                        self.client,
+                        mxc_url,
+                    )
+                    b64 = (await asyncio.to_thread(base64.b64encode, body)).decode('utf-8')
+                    await self.logger.info(
+                        f'[{_b.user_id}] Bridge 发送了二维码，请扫码登录:',
+                        images=[platform_message.Image(base64=f'data:{content_type};base64,{b64}')],
+                    )
                 except Exception:
                     await self.logger.error(
                         f'[{_b.user_id}] Failed to download bridge QR image: {traceback.format_exc()}'
@@ -672,11 +738,16 @@ class MatrixAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter):
 
     async def kill(self) -> bool:
         self._running = False
+        bridge_tasks = []
         for bridge in self._bridges:
             if bridge.login_task and not bridge.login_task.done():
                 bridge.login_task.cancel()
+                bridge_tasks.append(bridge.login_task)
             if bridge.check_task and not bridge.check_task.done():
                 bridge.check_task.cancel()
+                bridge_tasks.append(bridge.check_task)
+        if bridge_tasks:
+            await asyncio.gather(*bridge_tasks, return_exceptions=True)
         if self.client:
             await self.client.close()
         await self.logger.debug('Matrix adapter stopped')