f0a3aafda0
First content of the promotion chain. Brings the vendored SunSpec plugin, the Fronius vendor and its multi unit ID support: one froniusConnection thing now carries two SunSpecConnection objects, inverter and Smart Meter on separate unit IDs behind the same host and port. Verified before merging: 60 offline tests green, plus 8 green against the bench SunSpec simulator in froniusgen24-sunspec mode. Note: the branch was cut from the abbterra TCP line, so this merge also brings three abbterra commits that were never in main. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>