Meter detail: lead with periods and change, not register totals

The headline tiles were lifetime consumption, a raw reading count and the
register span. None of those answer why someone opens a meter: how much this
month, more or less than last, where the year lands, what it costs. A
cumulative counter's register value is an accident of when the meter was
installed.

MeterPeriodService buckets consumption by calendar month in the instance
timezone -- via date_trunc(... AT TIME ZONE) rather than EF grouping, because a
reading at 00:30 local on 1 January is 23:30 on 31 December in UTC and would be
booked to the wrong month (SDD §10). It reports generation for a generation
counter and consumption otherwise, so a PV meter stops claiming it consumed
0 kWh.

Month- and year-to-date are compared against a projection of the current period
rather than its running total. Three days into a month, "12 kWh vs 340 kWh last
month" reads as a collapse in usage when nothing has changed. The projection is
straight-line on elapsed days -- wrong for anything seasonal, but the honest
reading of "at this rate" -- and the UI marks it with a leading ~.

A 12-month bar strip gives the shape at a glance. A meter with nothing
normalized yet returns an empty history rather than a flat line, which would
look like a meter reading zero.

Register span, reading count and lifetime total move into a collapsed panel.
Still there when needed for an audit, no longer the first thing you see.

Claude-Session: https://claude.ai/code/session_01V6joyergfvVLFEizH1hJLd

src/Infrastructure/DependencyInjection.cs

@@ -43,6 +43,7 @@ public static class DependencyInjection
         services.AddScoped<Costing.CostService>();
         services.AddScoped<Dashboard.DashboardService>();
         services.AddScoped<Dashboard.SolarService>();
+        services.AddScoped<Dashboard.MeterPeriodService>();
         services.AddScoped<Dashboard.ConsumableService>();
         services.AddScoped<Dashboard.MeterDetailService>();
         services.AddScoped<Dashboard.FlowService>();