OPT-11 P4 review: Cheap hours ignores the plan; midnight-stale forecast; stricter ids

- Cheap hours only fills to the ceiling with or without a forecast, as the
  design (section 1) says. Skipping the sun's share cost 0.31 EUR on real
  2026 prices (29.72 against P3's 29.41) and saved nothing on the P3 set.
- A forecast reading from before local midnight is stale: until the
  integration refreshes, "left today" is still yesterday's 0 and
  "tomorrow" is really today.
- Forecast entity ids must be sensor.[a-z0-9_]+ (they go into the
  /api/states/<id> path).
- House profile: a stored day that is not a date, or is after today, is
  dropped instead of kept forever.
- Text: the forecast line says "for the rest of today"; the learning line
  no longer promises "tomorrow" (a plan needs one full day).
- Tests for four surviving review mutants (hour sample floor, the dear run
  after the cheap run, share by room, daytime use) and the fixes above.
- Replay tool: `--fc zero` (a forecast of no sun).

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

goodwe_controller/DOCS.md

@@ -545,7 +545,7 @@ With battery modes on, these choices replace the *Charging and selling on price*
 - *Solar first* never charges from the grid.
 - The house use is the add-on's own measurement (grid + battery power) per hour, over the last 7 days. It needs one day of it before the first plan.
 - The plan is checked every 15 minutes. A planned level moves only by 1 kWh or 10 %, so a wobbling forecast does not flip it.
-- No forecast, one older than 3 hours, or no house use yet: *Leftover solar* takes solar only and *Cheap hours only* fills to the top level. The Batteries screen says so.
+- No forecast, one older than 3 hours or from before midnight, or no house use yet: *Leftover solar* takes solar only and *Cheap hours only* fills to the top level. The Batteries screen says so.
 - A battery needs its capacity (`inverters.capacity_kwh`) for a plan.
 
 **What always comes first.**