Checking PR #29830: trafficshaper: add nftables firewall backend (Formalities Audit)

✅ Pull request originates from a dedicated feature branch (trafficshaper-nft-backend)

Commit 3340285 - trafficshaper: add nftables firewall backend:

✅ Author and committer identities are valid
✅ Commit is not a merge commit
✅ Commit subject layout and length are valid: "trafficshaper: add nftables firewall backend"
✅ Commit description lines adhere to width formatting rules
✅ Commit contains a consistent and valid 'Signed-off-by:' line
⚠️ Warning: No reference link (e.g., upstream release notes, changelog, or history URL) detected in description.
⚠️ Warning: Commit is unsigned or cryptographic signature verification failed (Reason: unsigned). Signing commits is a recommended best practice for verifying identity, but is not mandatory.