feat(kernel): admit SCTP protocol 132

[kernalix7]

Summary

• add tableless SCTP CRC32c and stateless RFC 9260 packet validation
• validate chunk framing, known shapes, INIT-family parameters, and bundling rules
• dispatch IPv4 protocol 132 with SCTP-local fragment rejection and saturating admission counters

Verification

• 85 focused SCTP tests
• 29 GRE regression tests
• 4,735 host unit tests
• 85 SCTP tests under Miri
• cargo fmt, Clippy with -D warnings, and workspace build
• aarch64 and riscv64 cross-builds
• x86_64, aarch64, and riscv64 QEMU boot suite