UX-13 P4 review fixes (PR #146, comment 1887)

R1: first_start also needs a Store created at this boot (Store.fresh), so
    old never-started sites (both TEST-23 add-ons, one in shadow) stay on Home.
R2: a kettle skip after a fall says on the last step that the reading went down.
R3: the shadow switch goes only on the model the wizard posts, never into V.
R4: Home Assistant not answering is red on the last step.
R5: meter + solar + battery below -300 W flags a reversed battery sensor.
R6: the live checks say what to change and where.

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

goodwe_controller/DECISIONS/UX-13-setup-wizard.md

@@ -23,14 +23,17 @@ The page opens `#setup` only when it is opened with no route, and only when
 `/config/model` gives a reason:
 
 - **`no_power_request`**: the stored options name no inverter to control.
-- **`first_start`**: the Store has no `setup_done` and no `auto` key, and
-  control is not started. `auto` is the key Start/Stop writes, and
-  config.yaml ships `auto_start` off (the same "fresh install" reading as
-  app/shadow.py's `auto` default), so this is a site that has never run or
-  been stopped by hand and never finished the wizard.
+- **`first_start`**: this boot found no `/data/state.json` (`Store.fresh`), the
+  Store has no `setup_done` and no `auto` key, and control is not started.
+  `auto` is the key Start/Stop writes. The startup gate exits 78 before the
+  controller writes the Store, so a new install's first good boot is fresh.
 
-A site that runs control, or ever started or stopped it, is never sent to the
-wizard. Without a Store the answer is no. The wizard's save writes
+"Never started" alone is not enough: both TEST-23 add-ons have `auto_start`
+off and no `auto` key, and one has run in shadow for weeks (review of PR #146,
+R1). So a Store read from a file is an old site, and it is never sent to the
+wizard. A new install that restarts before the page is opened is not sent
+either, and its Setup tab still works. A site that runs control, or ever
+started or stopped it, is never sent. Without a Store the answer is no. The wizard's save writes
 `setup_done` (an ISO time) to the Store. A save from the Installer view does
 not.
 
@@ -52,13 +55,16 @@ off, a fall turns it on. For a net entity or import and export, a fall cannot
 be fixed by an option, so the step is not passed and the page says what to
 check. A meter the add-on reads itself (HomeWizard, MQTT) cannot be read by
 the page, so the test is skipped and Home shows the direction after the
-restart. The installer may skip the test; the last step then warns.
+restart. The installer may skip the test, because a cloud can fake a fall;
+the last step then warns, and after a fall it says the reading went down.
 
 The battery and solar signs cannot be forced from the page, which never
 commands an inverter. The last step reports each battery's reading with its
 direction ("reads 800 W charging now, so check the inverter shows the same")
 and warns when a solar entity reads below zero without its "reads negative"
-switch.
+switch. It also warns when meter + solar + battery, all known, add up to a
+house using less than -300 W: a battery sensor reversed while giving power.
+An idle or charging battery cannot be judged that way.
 
 ## 4. The last step
 
@@ -67,12 +73,14 @@ It reads nothing itself: `web.py` passes a Home Assistant entity list at most
 5 s old, the running options, the running meter reading and today's price
 count. Tiers are ok, info, warn and bad. A power request entity missing from
 Home Assistant is **bad**, because a write to it is answered 200 (SAFETY-77)
-and only the entity list can tell. The wizard does not save while anything is
+and only the entity list can tell. So is Home Assistant not answering, since
+the list is then unknown. The wizard does not save while anything is
 bad. It then saves through P2's path (`setup: "done"`) and asks for the
 restart as the second, confirmed request, with a dialog that names the 0 W.
 The shadow switch is on by default and writes `shadow_mode: on`, which holds
 every inverter at 0 W after a restart even if control is started. Off keeps the
-stored value, or `auto` if that was `on`.
+stored value, or `auto` if that was `on`. The switch goes only on the model the
+wizard posts, never into the page model the Installer view also saves.
 
 ## 5. The stale save lists only what moved (P2 test, finding a)