Improvements and fixes

The metric editor's assistant no longer hangs on a proposal. It applies each proposal as it arrives.

• A solar string with no tilt value no longer reads as needing attention on the components page.
• The day graph on the battery dashboard shows the day-ahead price as a reference line across the full delivery day.
• Each battery dashboard tile now explains how its figure is evaluated.
• The plant controller onboarding wizard offers a "Re-probe" button that re-runs the probe.
• A chosen light or dark theme is shared across Mirox pages.