Readers (ndiout, fakesink) now handle MXL_ERR_FLOW_INVALID by releasing
and recreating the flow reader, then realigning the index to current time.
This lets consumer nodes survive a producer restart without exiting.
All mxlCreateInstance/FlowWriter/FlowReader options args changed from
nullptr to "" to match MXL reference implementation style.
mxlReleaseFlowReader calls guarded with null checks so cleanup is safe
when a mid-run reconnect attempt fails.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
studio-manager: call mxlGarbageCollectFlows before launching nodes to
clean up stale flow directories left by previous crashed runs.
shared/NodeBase.hpp: add mxl_status_str(mxlStatus) — converts error
codes to readable names (e.g. MXL_ERR_OUT_OF_RANGE_TOO_LATE). All
nodes now log these names instead of raw integers.
shared/FlowDef.hpp: use "audio/float32" as media_type for 32-bit audio
flows, matching the MXL SDK examples. audio/L{n} kept for other depths.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>