fix: document cleanup logic and mock Celery task in tests & some UI fixes

[AnishSarkar22]

Description

• Updated the document cleanup logic to correctly append remaining IDs when the response status is not 200, preventing potential data loss during cleanup failures. Additionally, added a fixture to mock the Celery delete task in CI environments so that tests no longer require a running broker connection.
• Some UI fixes.

Motivation and Context

FIX #

Screenshots

API Changes

• This PR includes API changes

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactoring
• Documentation
• Dependency/Build system
• Breaking change
• Other (specify):

Testing Performed

• Tested locally
• Manual/QA verification

Checklist

• Follows project coding standards and conventions
• Documentation updated as needed
• Dependencies updated as needed
• No lint/build errors or new warnings
• All relevant tests are passing

High-level PR Summary

This PR fixes document cleanup logic in the backend test suite and adds Celery task mocking for CI environments, along with several UI improvements in the web application. The backend changes ensure that document cleanup properly handles all non-200 status codes (not just 409) and mocks the Celery delete task to avoid broker dependencies during testing. The frontend changes address a race condition in the connector dialog state management, improve the report panel's right panel collapse/expand behavior, enhance the agent tools popover UI with scroll indicators and mobile responsiveness, fix dropdown menu z-index issues in the sidebar, and make various minor UI refinements including icon updates and connector display improvements.

⏱️ Estimated Review Time: 30-90 minutes

💡 Review Order Suggestion

Order	File Path
1	surfsense_backend/tests/integration/document_upload/conftest.py
2	surfsense_web/atoms/chat/report-panel.atom.ts
3	surfsense_web/components/assistant-ui/connector-popup/hooks/use-connector-dialog.ts
4	surfsense_web/components/assistant-ui/thread.tsx
5	surfsense_web/components/layout/ui/sidebar/DocumentsSidebar.tsx
6	surfsense_web/components/layout/ui/sidebar/ChatListItem.tsx
7	surfsense_web/components/layout/ui/sidebar/Sidebar.tsx
8	surfsense_web/components/layout/ui/sidebar/SidebarUserProfile.tsx

[vercel]

@AnishSarkar22 is attempting to deploy a commit to the Rohan Verma's projects Team on Vercel.

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[recurseml]

Review by RecurseML

🔍 Review performed on eec4db4..851856a

✨ No bugs found, your code is sparkling clean

✅ Files analyzed, no issues (8)

• surfsense_backend/tests/integration/document_upload/conftest.py
• surfsense_web/atoms/chat/report-panel.atom.ts
• surfsense_web/components/assistant-ui/connector-popup/hooks/use-connector-dialog.ts
• surfsense_web/components/assistant-ui/thread.tsx
• surfsense_web/components/layout/ui/sidebar/ChatListItem.tsx
• surfsense_web/components/layout/ui/sidebar/DocumentsSidebar.tsx
• surfsense_web/components/layout/ui/sidebar/Sidebar.tsx
• surfsense_web/components/layout/ui/sidebar/SidebarUserProfile.tsx