feat(platform): Phase 877 RPC wire view snapshot + responder hardening (v0.8.844)
Non-breaking: expose protomux-rpc opt-in flags via buildRpcWireViewSnapshot()
on platform view; guild sync/member page RPC responders use markRpcResponse;
listGuildGossipRpcRequestMethodKeys() for diagnostics. Default gossip v1
unchanged; fleet v2 cutover remains deferred.
Tests: test:ci-phase877 (boot gate, unit, view snapshot, method maps, live digest RPC).
Docs: PLATFORM_ROADMAP, PROTOMUX_RPC_MIGRATION, AUTOMATED_TESTING, release notes.