Echo is the authority the ircd account module forwards to: parse
ENCAP <us> SWACCTREG <reqid> <origin> <kind> <account> <p2> :<p3> into an
account request, and answer the origin server with
ENCAP <origin> SWACCTRES <reqid> <kind> <account> <status> <code> :<message>.
Thread the origin through the reply so responses route back to the
requesting server. Replaces the placeholder ACCTREGISTER/ACCTREGRESULT
names that nothing on the wire actually spoke.
Rebrand the daemon and workspace: the binary is now `echo`, every crate
is `echo-*` (`echo-api` and the module crates), Rust imports use
`echo_*`, the gRPC proto is `proto/echo.proto` with package `echo.v1`,
and the log filter, gossip peer-name default, and on-disk store default
(`echo.db.jsonl`) follow. Docs updated throughout. No behaviour change;
crate directories and the config schema are untouched.
The protocol link is a different kind of module from the service
pseudo-clients, so give it its own home: modules/inspircd ->
modules/protocol/inspircd. A future ircd link is a new crate alongside
it. Workspace member, dependency path, the crate's own api path, and the
docs are updated to match. No code change.
