Bump MCPG to v0.2.30 and AWF firewall to v0.25.28

[lpcox]

Summary

Bump the default MCP gateway and AWF firewall versions:

• MCPG: v0.2.26 → v0.2.30
• Firewall: v0.25.26 → v0.25.28

Changes Required

pkg/constants/version_constants.go

// Before
const DefaultFirewallVersion Version = "v0.25.26"
const DefaultMCPGatewayVersion Version = "v0.2.26"

// After
const DefaultFirewallVersion Version = "v0.25.28"
const DefaultMCPGatewayVersion Version = "v0.2.30"

Post-change steps

make build       # Rebuild binary (versions are embedded)
make recompile   # Regenerate all .lock.yml files with new versions
make test-unit   # Verify no regressions