[Crash] Unchecked msg.url access in feedback handler

[coderabbitai]

Summary

Services server crashes when msg.url is undefined in feedback handler.

Affected Code

server-services/start-services.js:577

avatar_url: msg.url + 'favicon.ico', // CRASH if msg.url is undefined

Vulnerability

If client sends {"cmd":"feedback"} without url field.

Impact

• Services server crash on feedback
• Denial of service

Proof of Concept

{"cmd":"feedback","email":"test@test.com","comments":"test"}

Recommended Fix

avatar_url: (msg.url || '') + 'favicon.ico',
embeds: [{ description: \`> from ${msg.email || 'unknown'}\\n\\n${msg.comments || ''}\` }]

References

• PR: New Blocks & Ported fancyMuzzle flash #43