CRITICAL fixes:
- Mask SNMP community string in agent channel logs (CRITICAL-1)
- Remove snmpv3 passwords from REST API responses, return _set booleans (CRITICAL-2)
- Replace snmp_community with snmp_community_set in GraphQL type (CRITICAL-3)
HIGH fixes:
- Fix cookie same_site from invalid 'Towerops' to 'Lax' (HIGH-4)
- Remove unsafe-eval from CSP script-src (HIGH-6)
- Block GraphQL introspection queries in production (HIGH-7)
- Sanitize LIKE wildcards in SNMP device name search (HIGH-8)
- Reject webhooks when no secret configured instead of accepting (HIGH-9)
MEDIUM fixes:
- Hash mobile session tokens (SHA-256) before DB storage (MEDIUM-10)
- Apply security headers in all environments, not just prod (MEDIUM-14)
- Add GraphQL query complexity limit (500) in production (MEDIUM-16)
- Fix X-Frame-Options to DENY to match frame-ancestors 'none' (MEDIUM-13)
