OPT-11 P3: price runs per battery

Cheap and expensive hours as runs of consecutive firm price slots
(priceruns.py); each battery's role per tick from its mode (modetrade.py):
grid charging for Leftover solar / Cheap hours only, never Solar first;
holding for the expensive runs; selling per battery (pack_sell) above the
spread and the floor. The site trade is sized inside the modes (loop bound)
and the peak guard's headroom; a run edge reseeds the loop. Cheap hours only
and selling are enabled on the Batteries screen and in the HA select
(appended). The site Why row no longer says "held back" when the peak limit
pushes power up (F2). Modes off: byte-identical to 7a00f12 on the trade path.

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

goodwe_controller/test_modes.py

@@ -335,11 +335,11 @@ _bad = [asyncio.run(_c.handle_action("pack_use", unit="inverter-z",
         asyncio.run(_c.handle_action("pack_use", unit=A, value=0)),
         asyncio.run(_c.handle_action("pack_use", unit=A, value=1)),
         asyncio.run(_c.handle_action("pack_mode", unit=A,
-                                     value=packmode.CHEAP_HOURS)),
+                                     value="sell_only")),
         asyncio.run(_c.handle_action("pack_mode", unit=A, value=None))]
 check("an unknown battery, a switch that is not true or false (0 and 1 "
       "included), and a mode "
-      "this release does not offer (Cheap hours arrives in P3) are refused, "
+      "that does not exist are refused, "
       "with a plain reason, and store nothing",
       all(isinstance(x, dict) and set(x) == {"error"} for x in _bad)
       and unit_key(A, packmode.MODE_KEY) not in _c.store.data