TARIFF-24: battery modes start the tariff task (hotfix 0.19.1)

With battery modes on, a day/night or fixed static_profile, no price feed and
arbitrage off, tariff_refresh_wanted() was false: no tariff task, no
tariff_plan, mode_runs None, so Leftover solar / Cheap hours never charged from
the grid and the Batteries screen said "No prices". packmode.enabled(opts) is
now a third term of the gate. With price_provider off the task is pure
arithmetic on static_profile, so no HTTPS call is added.

Also: version 0.19.1, CHANGELOG entry, DECISIONS note, test_tariff24.py, and a
shorter tariff_refresh_wanted() docstring (history stays in DECISIONS).

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

goodwe_controller/app/main.py

@@ -174,57 +174,17 @@ TARIFF_MAX_AGE_S = 3 * TARIFF_REFRESH_S
 
 
 def tariff_refresh_wanted(opts: dict) -> bool:
-    """TARIFF-10. Does this install need the background tariff refresh at all?
+    """Does this install need the background tariff refresh? (TARIFF-10, TARIFF-24)
 
-    THE DEFECT THIS PREVENTS, and it shipped: the gate below used to be
-    `arbitrage.enabled(opts)` alone. That option defaults to `false`, and
-    `run_tariff_refresh` is the only caller of `resolve_tariff()`, which is the
-    only caller of `price_history.carry()` - so on a shipped install with a
-    provider configured NOTHING was ever fetched, no plan was ever resolved,
-    `/data/price_history.json` was never created, the *Price history* row read
-    `empty` forever, and TARIFF-09's short-horizon warning could not fire
-    because there was no fetch to warn about. Measured over a 40 h soak of two
-    instances side by side: zero feed requests and `present: false` across all
-    802 samples on the shipped default, against a resolved plan from the same
-    feed on the instance with arbitrage armed. ⚠️ AND `DOCS.md` HAS
-    DESCRIBED THE BEHAVIOUR BELOW SINCE THE COMMIT THAT WROTE THE GATE:
-    OPT-04 (bdd7f18) added the refresh task, the `arbitrage.enabled()` guard on
-    it, and the sentence saying a configured provider still fetches, all in one
-    change. config.yaml has said it since TARIFF-02 (852fc7c).
-
-    Two terms, and they answer two different questions:
-
-      provider_configured(opts) -> "the operator asked for a price feed", so
-                                   fetch it, validate it and record the day
-                                   (§8.3). This is the term TARIFF-10 ADDS.
-      arbitrage.enabled(opts)   -> "the operator armed trading". This term is
-                                   what the gate USED to be, kept verbatim.
-
-    ⚠️ IT IS AN `or`, SO THE GATE IS A STRICT WIDENING. Every configuration
-    that started this task before still starts it; none that did not start it
-    stops anything. That matters because the second term is not redundant:
-    `price_provider: off` + a `static_profile` + `arbitrage_enabled: true` is a
-    configuration validate.py explicitly ACCEPTS, and it trades - measured, at
-    `cycle_cost_threshold_eur: 0.05` on a 0.20/0.284 day/night profile,
-    `ARBITRAGE_CHARGE -5000 W`. Dropping that term to make the gate read
-    `provider_configured(opts)` alone would leave `self.tariff_plan` at None on
-    that site forever and `decide()` would answer "no tariff plan has been
-    resolved yet" on every cycle - silently disarming a strategy the UI says is
-    running, which is the exact failure validate.py's OPT-04 rules exist to
-    refuse.
-
-    ⚠️ AND NO CONFIGURATION ACQUIRES A PERIODIC HTTPS CALL FROM THIS TICKET.
-    With `price_provider` off, `resolve_tariff()` returns `static_plan()` - pure
-    arithmetic, no socket - so the second term starts a task that fetches
-    nothing. The true shipped default (no provider, no arbitrage) starts no
-    task at all. What is fetched is decided by the FIRST term only.
-
-    ⚠️ THIS IS NOT A TRADING SWITCH. It decides whether prices are LOOKED UP.
-    Whether they move energy is `arbitrage.enabled()` at the one call site in
-    `cycle()`, and TARIFF-10 did not touch it: `arbitrage_enabled: false` still
-    means no trade, ever, on any configuration.
+    Yes with a price feed, with trading on price armed, or with battery modes
+    on: the modes read `self.tariff_plan` for their price runs. With
+    `price_provider` off the refresh is pure arithmetic on `static_profile`, so
+    no term here adds an HTTPS call. It decides whether prices are looked up,
+    never whether energy moves. See DECISIONS/TARIFF-10-fetching-is-not-trading.md
+    and DECISIONS/TARIFF-24-modes-need-the-tariff-task.md.
     """
-    return provider_configured(opts) or arbitrage.enabled(opts)
+    return (provider_configured(opts) or arbitrage.enabled(opts)
+            or packmode.enabled(opts))
 
 
 def load_options() -> dict:
@@ -8051,11 +8011,9 @@ async def amain() -> None:
         # ESP32 heartbeat. A fetch on that path is a supplier's TLS timeout able
         # to push this add-on towards layer 1's 30 s veto. See TARIFF_REFRESH_S.
         #
-        # ⚠️ STARTED WHEN A PROVIDER IS CONFIGURED, *OR* WHEN TRADING IS ARMED
-        # - TARIFF-10, and it used to be the second term alone. `arbitrage_
-        # enabled` ships `false`, so a site that had selected a price feed
-        # fetched nothing at all; the whole argument, the measurement and what
-        # the `or` is protecting are in `tariff_refresh_wanted()` above.
+        # ⚠️ STARTED FOR A PROVIDER, FOR ARMED TRADING OR FOR BATTERY MODES:
+        # see `tariff_refresh_wanted()` above and DECISIONS/TARIFF-10 and
+        # TARIFF-24 for why each term is there.
         #
         # ⚠️ IT DOES NOT ARM ANYTHING. Fetching a price and trading on one are
         # two decisions; this is the first, and `cycle()`'s