Improvements and fixes

Raw data can now be exported for a single inverter, combiner box or string.

• The raw data tab offers a "Detail level" — park, inverter, combiner box or string — then the components, merged or split into columns.
• The production page now labels the grid line "Feed-In", and the "Production Inv." overlay survives a refresh and a shared link.
• The day power curve now shows expected production from the plant's own irradiation sensor, or from weather data when it has none.