Upstream drift: CamM2325/microlink

[github-actions]

Open upstream PRs not yet recorded in UPSTREAM_PRS.md

• #33 — perf: add a zero-copy pbuf output path for WireGuard
• #32 — fix: stop dropping WireGuard packets silently on the receive path
• #31 — perf: cache the DISCO X25519 shared secret
• #30 — perf: move per-packet datapath logging to DEBUG
• #29 — Make ML_DERP_REGION a Kconfig option instead of a hardcoded #define
• #28 — Fix ci: bump actions/setup-python to v7 to drop the Node 20 runtime warning #17 plus five more lwIP thread-safety violations (found via CONFIG_LWIP_CHECK_THREAD_SAFETY)

Checked 2026-08-31T13:56Z against @ .