Improvements and fixes

A plant's core data gains a "Yield report" tab, report charts are set per series, and the web app opens faster.

• A plant's core data has a "Yield report" tab: monthly performance ratio and irradiation targets, with expected production calculated from them.
• A month with no yield-report value uses a default, and a performance ratio far from that month's typical value is marked "Unusual".
• Report charts can be set per series to bar or line, stacked, filled, with up to two unit axes, or drawn as a heatmap.
• Each report block can carry its own period, chosen in the editor and the wizard, independent of the report's period.
• The cell balance card of an INTILION storage now names where the weakest and strongest cell and the hottest module sit.
• The web app opens faster: the first page loads only what it needs, and only the language in use.