OPT-17: the solar forecast can come from several entities, summed

New list options pv_forecast_entities and pv_forecast_tomorrow_entities
(same shape as pv_entities); the single-entity keys are unchanged.

- Each member is read in its own unit (Wh/kWh/MWh) in one gather and the
  day is summed. Hourly splits are merged when every member has one, else
  the total goes on the bell.
- A member missing, unavailable, stale, non-energy or bad makes that
  day's forecast unusable (no partial sum). A caution row names it by
  position; the action log names the entity once per change.
- Single key and list both set for one day: refused at start.
- A one-member list behaves exactly like the single key (test_opt17.py);
  the single-key path is byte-identical to e36565f over 24 scenarios.
- Supervisor shape measured: tools/supervisor_shape_probe.py section J.

DECISIONS/OPT-17-several-forecast-entities.md has the rules.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bdqr7PiaHcBnzPituu2yTC

goodwe_controller/app/main.py

@@ -992,12 +992,17 @@ class Controller:
         self._charge_blocked_q = None
         self._ref_cheap = None
         # OPT-11 P4: the solar forecast and the day plan. Only with battery
-        # modes on AND `pv_forecast_entity` set; otherwise none of this runs
-        # and every mode acts as in P3 option A.
-        self.fc_entity = (opts.get("pv_forecast_entity") or None) \
-            if self.modes_on else None
-        self.fc_tomorrow_entity = opts.get("pv_forecast_tomorrow_entity") \
-            or None
+        # modes on AND a forecast for today set; otherwise none of this runs
+        # and every mode acts as in P3 option A. OPT-17: each day may name
+        # several entities, summed (`solarfc.entities()`); `fc_entity` is
+        # the first, and None means no forecast.
+        self.fc_entities = (solarfc.entities(opts) if self.modes_on
+                            else ())
+        self.fc_tomorrow_entities = solarfc.entities(opts, tomorrow=True)
+        self.fc_entity = self.fc_entities[0] if self.fc_entities else None
+        # OPT-17: the members that are not usable, as `solarfc.read_sum()`
+        # gives them, for the status page and the action log.
+        self.solar_fc_gaps = ()
         self.solar_trust_pct = opts.get("solar_trust_pct",
                                         dayplan.DEFAULT_TRUST_PCT)
         self.solar_fc = None
@@ -3246,18 +3251,31 @@ class Controller:
     async def _read_forecast(self) -> None:
         """OPT-11 P4: the solar forecast sensors (`solarfc.read()`). A
         failed or stale read is no forecast, never a zero."""
-        today = await self.hass.state(self.fc_entity)
-        tomorrow = (await self.hass.state(self.fc_tomorrow_entity)
-                    if self.fc_tomorrow_entity else None)
+        # OPT-17: every member of both days in one gather.
+        ents = self.fc_entities + self.fc_tomorrow_entities
+        states = await asyncio.gather(*(self.hass.state(e) for e in ents))
+        n = len(self.fc_entities)
         now = datetime.now(timezone.utc)
-        fc, why = solarfc.read(today, tomorrow, now)
-        if (fc is None) != (self.solar_fc is None) or why != self.solar_fc_why:
+        fc, why, gaps = solarfc.read_sum(
+            list(zip(self.fc_entities, states[:n])),
+            list(zip(self.fc_tomorrow_entities, states[n:])), now)
+        # A member is named only in a sum of several; one entity reads as
+        # before. Logged once per episode: on a change, never every read.
+        gaps = tuple(g for g in gaps if len(
+            self.fc_entities if g[0] == "today"
+            else self.fc_tomorrow_entities) > 1)
+        if (fc is None) != (self.solar_fc is None) \
+                or why != self.solar_fc_why or gaps != self.solar_fc_gaps:
             self.log_event(
                 "solar forecast: " + ("read" if fc is not None else
-                                      f"none ({why})"),
-                hint=messages.hint("forecast_read" if fc is not None
-                                   else "forecast_none"))
+                                      f"none ({why})")
+                + "".join(f", {d} {e} not usable ({w})"
+                          for d, _i, e, w in gaps),
+                hint=messages.hint(
+                    "forecast_none" if fc is None else
+                    "forecast_no_tomorrow" if gaps else "forecast_read"))
         self.solar_fc, self.solar_fc_why = fc, why
+        self.solar_fc_gaps = gaps
 
     async def read_inputs(self, now_mono: float | None = None) -> None:
         """Every input this cycle needs, and SAFETY-37's freshness verdict.
@@ -6998,6 +7016,17 @@ class Controller:
             # is both is a check nobody reads.
             out.append({"ok": False, "warn": True, "id": "peak_forecast",
                         "text": messages.row_no_peak_forecast()})
+        # OPT-17: a forecast summed from several entities names, by position,
+        # each member with no usable reading. A caution: control goes on.
+        gaps = getattr(self, "solar_fc_gaps", ())
+        for day, ents in (("today", getattr(self, "fc_entities", ())),
+                          ("tomorrow",
+                           getattr(self, "fc_tomorrow_entities", ()))):
+            gone = [i for d, i, _e, _w in gaps if d == day]
+            if gone:
+                out.append({"ok": False, "warn": True, "id": "solar_forecast",
+                            "text": messages.row_forecast_gap(
+                                day, gone, len(ents))})
         # --- TEL-11 ----------------------------------------------------------
         # ⚠️ NO ROW AT ALL WHEN THE ROSTER IS EMPTY, AND THAT IS A DELIBERATE
         # DIFFERENCE FROM THE PEAK-FORECAST CAUTION DIRECTLY ABOVE. That one