Wires up the two links that made session resume unreachable: MemberSession
now records agentSessionId from PeerHandle at acquire (both the plain and
worktree paths), and it survives onto the roster (rosterView, so both
bridge_list and GET /members show it). bridge_spawn accepts sessionName and
resumeSessionId, threading them into the SpawnRequest fields that already
existed but were never reachable from the MCP surface.
A resumeSessionId now requires an explicit profile (a resumed conversation
is tied to the specific backend that started it, so an unqualified spawn
routed by placement has no safe candidate to check) and is refused, naming
Capability.SESSION_RESUME, when that profile's adapter does not declare it
— PeerLauncher gains capabilitiesFor(profileName) so a mixed fleet is
checked per-adapter rather than against the fleet-wide capability union.
PeerHandle.agentSessionId() loses its default, the same fix CB-571 (c00a86b)
made for charterReceipt() one method above it — both existing adapters
already overrode it, so this only closes the landmine for a future one.
Out of scope, left for follow-up: carrying agentSessionId on a failed
ticket's ReleaseDetail (issue #65 criterion 5) — CB-578 stage C just
landed in that file and this ticket deliberately stayed out of it.
Dai Ha
5d5b3bdc76