UX-13 P0 review: keep unread keys, back off a failed entity read

- uimodel: editing a listed inverter keeps the stored flat keys, and a
  region of "own" keeps a stored price_taxes_profile (both were dropped).
- haentities: a failed read also waits CACHE_S, so polls while Home
  Assistant is down do not queue one 10 s read each.
- ui_text: the Flanders preset names its DSO, and the help says
  Wallonia and Brussels have no figures yet. REGION_PRESETS cites the card.
- tests: decode of a reversed solar row, both kept keys, the backoff.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

goodwe_controller/app/haentities.py

@@ -51,13 +51,17 @@ class EntityCache:
         self.clock = clock
         self.rows: dict | None = None
         self.read_at: float | None = None
+        self.tried_at: float | None = None
         self._lock = asyncio.Lock()
 
     async def get(self) -> tuple[dict | None, float | None]:
         """(rows by entity id, age in s), or (None, None) if never read."""
         async with self._lock:      # one HA read however many pickers ask
             now = self.clock()
-            if self.read_at is None or now - self.read_at >= CACHE_S:
+            # A failed read also waits CACHE_S, so polls while HA is down do
+            # not queue one 10 s read each behind this lock.
+            if self.tried_at is None or now - self.tried_at >= CACHE_S:
+                self.tried_at = now
                 states = await self.hass.states()
                 if states is not None:
                     rows = (row(s) for s in states)

goodwe_controller/app/ui_text/en.json

@@ -20,7 +20,7 @@
   "fields": {
     "solar": {"name": "Solar inverters", "description": "Each solar inverter's power sensor, which the add-on records but does not use for control."},
     "contract": {"name": "Your contract", "description": "How your supplier prices each kWh you take from the grid."},
-    "region": {"name": "Region", "description": "Fills in the grid costs, levies and VAT for the year shown, so check them on your bill."},
+    "region": {"name": "Region", "description": "Fills in grid costs, levies and VAT for the year shown, but not yet for Wallonia or Brussels, so check your bill."},
     "fallback": {"name": "Price when the feed is down", "description": "Used when the price source does not answer."},
     "fixed_price": {"name": "Price per kWh, all in", "description": "Energy, supplier costs, grid costs, levies and VAT together."},
     "day_price": {"name": "Day price, weekdays 07:00 to 22:00", "description": "All in, as on your bill."},
@@ -29,7 +29,7 @@
   "choices": {
     "contract": {"none": "No prices", "fixed": "Fixed price", "daynight": "Day and night", "dynamic": "Dynamic, hourly", "custom": "Other time windows"},
     "fallback": {"none": "None", "fixed": "One price", "daynight": "Day and night", "custom": "Other time windows"},
-    "region": {"flanders": "Flanders", "own": "I enter my own figure"}
+    "region": {"flanders": "Flanders, Fluvius Antwerpen", "own": "I enter my own figure"}
   },
   "applies": {
     "restart": {"name": "Applies after a restart"},

goodwe_controller/app/uimodel.py

@@ -31,7 +31,8 @@ class DeriveError(ValueError):
 # --------------------------------------------------------------------------- #
 # Region presets for "Grid costs, levies and VAT". Year-stamped, updated each
 # January (owner, 2026-09-27). Only presets with a sourced figure are listed:
-# Flanders is app/price.py's Fluvius Antwerpen sum (TARIFF-18). Wallonia and
+# Flanders is app/price.py's Fluvius Antwerpen sum (TARIFF-18: Eneco
+# residential card, Flanders, September 2026, VAT included). Wallonia and
 # Brussels have a day and a night band (config.yaml) and join with sourced
 # figures; until then those sites choose "own".
 # --------------------------------------------------------------------------- #
@@ -93,9 +94,10 @@ def _roster_encode(m, keep):
         return out
     out["inverters"] = [{k: v for k, v in c.items() if v is not None}
                         for c in cards]
+    # The flat keys beside a list are not read: they stay as stored.
+    out.update({k: copy.deepcopy(keep[k]) for k in _ROSTER_FLAT if k in keep})
     if shape == "flat":
         # CFG-04 rule 9e: a flat power request entity beside a list is refused.
-        # The other flat keys stay as stored and are not read.
         out["setpoint_entity"] = ""
     return out
 
@@ -252,7 +254,10 @@ def _region_decode(o):
 def _region_encode(m, keep):
     region = m.get("ui.region")
     if region == OWN:
-        return {"price_taxes_eur_kwh": m.get("price_taxes_eur_kwh")}
+        out = {"price_taxes_eur_kwh": m.get("price_taxes_eur_kwh")}
+        if "price_taxes_profile" in keep:       # "own" keeps the stored table
+            out["price_taxes_profile"] = keep["price_taxes_profile"]
+        return out
     if region not in REGION_PRESETS:
         raise DeriveError(f"unknown region {region!r}")
     p = REGION_PRESETS[region]