Merge release/1.0 (TARIFF-10) into TARIFF-12

CHANGELOG.md was the only conflict: both entries belong under the same
`## Unreleased` heading, TARIFF-10's first because it merged first. No
version number picked.

app/main.py auto-merged, and was re-read because of it. TARIFF-10 changed
WHICH installs run `run_tariff_refresh()` (`arbitrage.enabled(opts)` ->
`tariff_refresh_wanted(opts)`); this card changed what that task does on
a failed fetch. Nothing in the keep/replace reasoning changed, and the
two newly reachable configurations are now DRIVEN in test_arbitrage.py
8b rather than reasoned about:

  * a provider configured with trading DISARMED is the case the guard
    was designed for, and needs no second fixture because nothing on
    this path reads `arbitrage_enabled` at all - asserted over the AST's
    symbols and non-docstring constants, after two drafts of that check
    went red on a CORRECT tree for matching the word "arbitrage" in a
    docstring and in a log line;
  * `price_provider: off` + a `static_profile` resolves to the
    CONFIGURED product (`origin: "static"`), so `standing.from_feed` is
    false on every refresh and the guard never latches - driven twice in
    a row, because a guard that latched there would freeze a static
    site's plan at its first window for the life of the install.

Also: the kept-plan log line said "arbitrage stops with it", which after
TARIFF-10 is false on a site that fetches without trading; it now says
"arbitrage, where it is armed, stops with it". The keep decision is
strictly downstream of `resolve_tariff()`, so the §8.3 carry into
price_history - TARIFF-10's whole point - is unaffected either way.

All 29 suites green on the merged tree, including TARIFF-10's new
test_price.py section 13. All eleven mutations RE-DRIVEN on the merged
tree rather than carried over: eleven red, no survivors, every revert
fingerprinted. M11 is new - making the guard conditional on
`arbitrage.enabled(self.o)` (+86 B) is red on five named checks.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU

goodwe_controller/app/static_tariff.py

@@ -207,7 +207,7 @@ from datetime import datetime, timedelta, timezone
 from .price import (
     MAX_PLAUSIBLE_EUR_KWH, Absence, PricePoint, PriceProduct, PriceRead,
     Uncertainty, _Outcome, brussels, load_prices, price_option,
-    required_spread, uncertainty_of, widen_factor,
+    provider_configured, required_spread, uncertainty_of, widen_factor,
 )
 
 _LOG = logging.getLogger("goodwe.tariff.static")
@@ -1098,8 +1098,7 @@ async def resolve_tariff(opts: dict, since: datetime, until: datetime,
     missing and loses the elapsed ones it should never have had.
     """
     stamp = now or datetime.now(timezone.utc)
-    pid = str(price_option(opts, "price_provider") or "off").strip()
-    if pid in ("", "off"):
+    if not provider_configured(opts):
         return static_plan(opts, since, until, provisional=False, now=stamp)
 
     read = await load_prices(opts, since, until, transport)