Fix YouTube and multiple upload Error

[martintony4all]

Summary

Adds ui_search_direct.py - a Streamlit UI that calls Azure APIs directly instead of through Azure Functions. This fixes the "400 Bad Request: property 'id' does not exist" error by automatically detecting the actual key field from the Azure Search index schema.

Problem Solved

• Azure Function EmbedAndIndex fails when index schema doesn't have id as key field
• Azure Function TranscribeHttp uses hardcoded Speech API version
• Blob upload SAS tokens fail due to incorrect string-to-sign format
• Poor error visibility makes debugging difficult

Solution

• Auto-fetch index schema to detect correct key field name
• Call Speech API directly with configurable API version
• Fixed REST API upload with correct canonicalized resource format
• Detailed error reporting with schema debugging UI

Testing

• YouTube URL processing
• Direct media URL processing
• File upload with blob storage
• Batch CSV processing

[aronwc]

@martintony4all There are a lot of changes here! I'm going to need you to walk me through them. It seems like there might be some code here that duplicates what's already in TranscribeHttp?

Also, I made some changes recently to ui_search.py that you'll need to incorporate.

It may be best to have a separate page like pages/2_upload_videos.py or similar so that this logic is outside of the ui_search.py file.

[martintony4all]

@aronwc The pull request now reflects the new multipage structure with separate page files (2_Upload.py, 3_Manage_Videos.py, 4_System_Diagnostics.py) and shared utils.py, as requested. The merge is complete, and there are no conflicts. Ready for PR review.