Record the M3.13d delivery and the next slice

[kaikisegfault]

Documentation only. docs/project/current-state.md, no source, build, workflow,
or vector change, so this is the focused metadata verification path.

What it records

• M3.13d is delivered: the version-seven transport is on main across
  cc8b9c0..115c295, and a version-seven application answers over a real Unix
  socket.
• How it was delivered: why there is no new frame format and no second
  connection loop, that the V1 in UnixSocketServerV1 names the wire rather
  than the ledger, what the finalize response carries that version one's does
  not, why every response is validated on the way out, and the explicit tagged
  chain-identity conversion that must not be "fixed" by loosening a type.
• Two probes that found missing tests, one of which is a pattern worth
  keeping: a socket test that aborted rather than failed, because an
  assertion inside the client block left the server thread unjoined and
  std::thread's destructor called std::terminate. A test that aborts instead
  of reporting is one that will eventually hide a real failure.
• What the transport looks like now, so a later session does not rediscover
  that there is no version-seven wire, where the shared loop lives, or that the
  finalize payload puts the block identifier after the state root.

The next slice

M3.13e, decode_genesis and the version-seven server binary, with the
obstacle stated rather than left to be met: version one's binary reads a genesis
file and hands the bytes to its store, while create_sqlite_ledger_v7 takes a
v7::Genesis struct and version seven publishes encode_genesis with no
inverse. The canonical encoding is 110 octets — the store's own
ledger_meta_v7 schema asserts exactly that — so a decoder over those octets is
the natural answer and its round trip against the encoder is the property to
test. The entry also carries what version one's --genesis-identity mode prints
and why the socket pathname bound matters.

Verification

python3 -B tools/verify_metadata.py — 5 repository skills and 264 internal
Markdown links validated. git diff --check clean. The hosted focused metadata
path is the gate for this exact commit.