Warn users when socket_org is missing and upload is skipped

[dc-larsen]

Summary

When using an API key that lacks the socket-basics:read scope, result uploads are silently skipped because socket_org cannot be auto-discovered. This leaves users confused about why their scan results don't appear in the dashboard.

This PR changes the log level from debug to warning and directs users to create an API key with the correct scopes.

Problem

A customer reported that scan results weren't uploading when using their existing SCA API key (which lacks socket-basics:read). The only indication was a debug-level log message that most users never see:

DEBUG - No Socket organization configured, skipping full scan submission

Solution

Upgrade to a warning that explains the issue and directs users to the fix:

WARNING - No Socket organization configured - scan results will not be uploaded to the dashboard. 
This typically means your API key is missing the 'socket-basics:read' scope. 
Please create an API key with the required scopes in Settings > API Tokens 
in the Socket dashboard (https://socket.dev).

Test plan

• Verified warning appears when socket_org is not configured
• Message directs users to create properly-scoped API key
• Test in GitHub Actions workflow with limited-scope API key