fix: enable secure network event defaults

[pushkart2]

Summary

• enable request-control filtering with the documented settle timer
• disable network-routed sounds, phone explosions, and script entity state changes
• use the current sv_enableNetworkedPhoneExplosions convar name

Security impact

The recipe now ships safer defaults for commonly abused routed network events while retaining explicit configuration points for operators who need compatibility overrides.

Validation

• git diff --check
• convar names checked against the Cfx.re server command documentation
• GitHub security checks will run on this draft