SMA-2: each inverter is reached through a driver; GoodWe behaviour unchanged

app/drivers.py holds one Driver per roster entry (configured, actuator_id,
limits, read, write, release, probe, link_stale_s, batt_bound, settle_s, brand,
words). GoodWeEsphomeDriver makes the calls the code it replaced made, in the
same order. Inverter gets driver; has_writer, is_live and link_note read it. The
SoC/power read, the write, the device range (run_control, amain, the settings
panel), rule 2 per unit and the SAFETY-28 census go through it.

setpoint_entity is optional per entry beside driver, host, port, unit_id and
maintenance; only goodwe_esphome is selectable, the rest are checked and unused.

Co-Authored-By: Claude <noreply@anthropic.com>

goodwe_controller/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Not in a release yet
 
+- Each inverter is now reached through a driver, so another make can be added later. Nothing changes for a GoodWe site, and the inverter list accepts five new optional settings that nothing reads yet ([[SMA-2]]).
 - Home now draws today's charge from the grid for every hour the add-on will really charge, not only the run under way ([[UX-77]]).
 - When Home Assistant passes readings on late, control no longer swings on them: it waits until the battery shows its last power request, and the peak limit no longer asks for full power on them. The page says so, and if the readings stay too late every inverter goes to 0 W ([[SAFETY-128]]).
 - With a 5 s meter, readings 30 s late are now noticed within 100 seconds, not 3 minutes ([[SAFETY-129]]).