v2.0.1

v2.0.1 — Unblock Fedi trades: generate-only ecash funding, idempotent native join

Compatible — no LOCK/escrow format change. Interops with any v2.x.x client
unchanged; safe drop-in over 2.0.0.

Fedi funding — stay on internal ecash without receiveEcash

• Escrow funding now gates on generateEcash alone (hasFediInternalGenerateEcash)
  instead of requiring generate + receive. Hosts that expose generateEcash but
  not receiveEcash — e.g. the Fedi Mini-App — now fund trades over the internal
  ecash route instead of falling back to a Lightning receive. This is what
  unblocks trading inside Fedi.
• Capability probe split into hasFediInternalGenerateEcash() /
  hasFediInternalReceiveEcash(); hasFediInternalEcash() now means both are
  present. Both new probes are exported from src/fedimint.

Native bridge — idempotent Fedimint join

• open_or_join() reuses the live client when its federation matches the invite,
  and fails loudly when the local client DB belongs to a different federation
  ("reset local state before switching federations") instead of attempting a
  conflicting join. AppState.join now routes through open_or_join.
• Bridge advertises an idempotent_join capability (/health, api_version 2); the
  native-bridge adapter requires reset + idempotent_join and names the missing
  capability in stale-sidecar diagnostics.