* refactor(agent-status): isolate legacy status ingress
* fix(agent-hooks): move advertised-capability source onto the ingest envelope
ingestRemote() gained a third positional argument in this PR
(advertisedAgentStatusCapabilities) to satisfy a new ratchet requiring
every legacy-ingress call site to name its capability source. Both
production callers pass the same constant every time, so the argument
carries zero runtime information — but Vitest's toHaveBeenCalledWith
matches argument count exactly, so the pre-existing SSH relay
integration test (which asserts a 2-argument call) started failing
even though nothing about the actual admission decision changed.
Capabilities are a property of the producing peer/connection, not an
orthogonal call parameter, so move the field onto the envelope object
instead of adding a third positional argument: ingestRemote reads
envelope.advertisedAgentStatusCapabilities (defaulting to the
unadvertised-legacy-peer set), and both call sites stamp the constant
onto their envelope literal. Call arity stays at two arguments, so the
pre-existing evidence test needs no change.
The envelope never crosses the wire in either caller: SSH rebuilds it
field-by-field from the RPC params, and the WSL path copies (never
mutates) the wire-deserialized notification before stamping the field
on, so this is purely an internal main-process shape change.
Also strengthens the ingress ratchet test that required this: it
previously only checked that the capability constant's name appeared
somewhere in each caller's source, which a stray unused import could
satisfy. It now asserts the actual
`advertisedAgentStatusCapabilities: AGENT_STATUS_LEGACY_UNADVERTISED_PEER_CAPABILITIES`
key:value binding is present.