On-device diagnosis (phone on adb, 5G): mesh sessions established but no
packet ever entered the tunnel — Android hands the VpnService TUN fd over
non-blocking, and the fips fork's dedicated blocking-read thread treats
EAGAIN as fatal, dying at startup. archy-fips-core now forces the fd into
blocking mode before Node::start_with_tun_fd. Verified on-device: reader
survives, packets flow into the mesh, and the 30s anchor-link flap is
gone (stable 8+ min on 5G).
Also setMetered(false): Android 10+ defaults VPNs to metered, flipping
the phone into data-restricted behaviour whenever the mesh is up.
Served APK: 0.5.4 (vc24). Handoff updated with the remaining node-side
blocker: phone->anchor works, phone->node ULA gets no reply — needs
fipsctl introspection on Framework PT (suspect fork/daemon session or
routing mismatch).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>