EV Balance 26.7.11

Time-of-use tariffs are now data-driven

Tariff bands are no longer hardcoded: they come from JSON presets under
custom_components/evbalance/tariffs/, so new countries can be added with a
simple pull request (validated in CI against a JSON Schema).

Highlights

• Data-driven tariff schemes with minute-level bands (HH:MM), seasonal
  schedules, weekend handling and national holidays (via the holidays library).
• Per-band cost rank — groundwork for future price-aware charging control.
• Ready-made country presets: 🇮🇹 IT (ARERA F1/F2/F3 + monoraria), 🇪🇸 ES,
  🇫🇷 FR, 🇵🇹 PT, 🇮🇪 IE, 🇬🇧 GB, 🇧🇪 BE, 🇳🇱 NL, 🇬🇷 GR, 🇵🇱 PL, 🇭🇷 HR, 🇸🇮 SI,
  🇩🇰 DK, 🇧🇬 BG, 🇨🇭 CH, 🇫🇮 FI, plus extra-EU examples (🇷🇺 RU, 🇮🇳 IN, 🇺🇸 US,
  🇨🇳 CN, 🇯🇵 JP, 🇰🇷 KR).
• Tariff editor in the panel: pick a preset (pre-selected by your Home
  Assistant country) or build/modify custom bands, saved per config entry.
• default single-rate tariff used when none is selected.

Compatibility

Fully backward compatible: existing setups keep their bands and energy
statistics. The historical arera/flat presets keep working through aliases,
so no reconfiguration is needed.