feat(pvforecast): add adaptive per-plane PV learning and diagnostics (#1422)

PV arrays with different orientations and curtailment need separate plant calibration and weather correction. This opt-in provider publishes normal EOS AC/DC forecast keys at 15-minute resolution.

- Preserve daily per-plane energy/shape calibration and validated short-term local/trend selection. Curtailment-sensitive arrays require a fresh release flag or an explicitly configured learning guard.
-  Add switchable empirical solar-angle response relative to separate eligible reference arrays, removing their common weather error. This learns angular residuals, not physical angles or a measured geometric horizon.
-  Archive actually received weather model inputs, first local receipt and frozen per-member PV candidates. Returned past weather is excluded; unknown source issuance remains explicit. Learn model weights and forecast-regime bias separately at 2–6, 6–24 and 24–48 hours.
- New long-horizon candidates remain in shadow until their genuinely issued outputs improve equal-day MAE by the configured margin, win on at least 60% of validation days and pass a matched-support energy-bias guard. Insufficient evidence retains calibration. Daily yields still require complete local days, including DST.
- Expose fitted parameters, independent training/validation day counts, errors, selected methods and persistence in the existing status API, with additional normal prediction keys for Grafana. Retain physical DC through angular/weather corrections an  enforce individual inverter AC limits.

Co-authored-by: Normann <github@koldrack.com>
Co-authored-by: Christin <chrissi@von-perbandt.de>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: YMT <yn276364@dal.ca>
Co-authored-by: sarankumar1325 <120080287+sarankumar1325@users.noreply.github.com>

tests/test_pvforecastpvlib.py

@@ -1,6 +1,7 @@
 
 """Tests for PVForecastPVLib prediction provider."""
 
+import os
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
@@ -487,7 +488,8 @@ class TestCECDatabase:
         #
         # Force new modification time.
         #
-        path.touch()
+        previous = path.stat()
+        os.utime(path, ns=(previous.st_atime_ns, previous.st_mtime_ns + 1_000_000_000))
 
         second = _load_cec_database(path)