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/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"},