Feat/zip upload connector

[Grandvizir]

Summary

Add a new ZIP upload connector that lets users import documents by uploading a .zip archive, fix connector creation form submission bugs, and improve error visibility during HTTP ingestion.

Changes

New: ZIP Upload Connector

• New connector type zipupload: Users can upload a .zip file containing documents (PDF, DOCX, TXT, MD, HTML, etc.) directly from the UI. The archive is stored via Django's pluggable storage backend (local filesystem by
  default, Azure Blob / S3 in production).
• connectors/zipupload.py: Connector implementation — lists files inside the zip, filters by supported extensions, skips macOS __MACOSX resource forks, and extracts individual files on demand for the ingestion pipeline.
• connectors/models.py: Added ZIPUPLOAD to ConnectorType choices.
• connectors/init.py: Register the new connector module.
• connectors/views.py: Handle zip file upload in connector_create (validation, storage), and serve individual files from the zip in document_file.
• score/settings.py: Added uploads storage backend config and UPLOAD_ROOT setting, with support for Azure Blob / S3 via environment variables.
• pyproject.toml / requirements.txt: Added optional django-storages[azure] and django-storages[s3] dependencies.
• connectors/migrations/0005_add_zipupload_connector_type.py: Migration for the new connector type.
• Templates: Added ZIP upload config panel (file input) and icon/title in both the modal (_connector_cards.html) and standalone create page (create.html).

Fix: Connector creation form not submitting

• Disable hidden required inputs: The Elasticsearch config_index input had a required attribute that silently blocked browser form validation when other connector types were selected. The JS updateModal() / update() functions
  now disable required inputs in hidden config panels and re-enable them when their panel becomes active.
• Add data-turbo="false": Prevents Hotwire Turbo from intercepting form submissions in both the modal and standalone create forms.
• Add visual validation feedback: The standalone create page now shows inline error messages and red borders on invalid fields.

Fix: HTTP connector documents not appearing

• connectors/generic.py: _fetch_http() now raises ValueError when the HTTP response body is empty (e.g. HTTP 202 Accepted), instead of silently producing an empty document.
• ingestion/pipeline.py: When text extraction fails or _process_document() raises an exception, the document is now created with ERROR status and an error message, instead of being silently skipped. Users can see failed
  documents in the connector detail view.

Test Plan

• Tests pass (pytest)
• Linting passes (ruff check .)
• Manual testing done:
  • Upload a .zip file via the modal → connector is created → sync → documents from the zip appear in the connector detail
  • Upload an invalid file (not a zip) → error message is displayed
  • View a document from a zip connector → file content is served correctly
  • Open connector list → click each connector type card → fill form → submit → connector is created for all types
  • Submit form with empty name → validation error is shown
  • Create an HTTP generic connector with a URL returning empty content → sync → document appears with ERROR status
  • Create an HTTP generic connector with a valid URL → sync → document appears normally

Related Issues

Closes #