Bundle of all phases (P0-P5) plus the diagnostic fixes from the
end-to-end test session: ephemeral peer/metrics ports, no reqwest
connection pool, short-poll inbox, expanded sidecar path probe.
Smoke-tested by exchanging messages with a second mycelium node in
a Docker container against the public Threefold seed
tcp://188.40.132.242:9651 — bidirectional delivery confirmed.
Built on Debian 12 (bookworm), x86_64, glibc-targeted but the
embedded mycelium binary is musl static.
