SDD §8 panels (PV/oil/meter-detail) + fix reference-data-in-Docker

Complete the SDD §8 dashboard views that were deferred at the M5 boundary,
and fix a shipping bug that left the Docker demo empty.

Bug: "Load reference data" created meters/tank/tariffs but imported zero
readings in Docker. Root cause: sampledata/ was excluded by .dockerignore and
never copied into the build stage, so the App csproj's linked Content glob
resolved to nothing at publish time; ReferenceDataImporter then silently
skipped the missing CSVs after already writing its marker meter, leaving the
DB permanently "loaded" but empty.
  - .dockerignore: stop excluding sampledata/
  - Dockerfile: COPY sampledata/ into the build stage
  - ReferenceDataImporter: fail-fast (validate CSVs exist before the marker
    meter) and throw instead of silently skipping a missing file
  - Program.cs + MeterVaultOptions: opt-in MeterVault__SeedReferenceData
    (compose METERVAULT_SEED=true) for a one-command populated demo

New SDD §8 panels (read models in Infrastructure/Dashboard, Blazor pages):
  - §8.4 Solar/PV (/solar): generation from GenerationCounter meters;
    self-consumption / autarky % / self-consumption % / savings derived from
    meters tagged total_load & grid_import via Meter.Meta role config
    (MeterRoles/MeterMeta) — nothing hardcoded by name.
  - §8.5 Oil/consumable (/consumables): tank level (cm→L calibrated), fill
    gauge, deliveries log, burner runtime, effective L/h (fixed/empirical),
    forecast-to-empty, tariff cost, monthly series.
  - §8.6 Meter detail (/meters/{id}): raw readings, normalized consumption,
    source status, tariff timeline, events, measured-vs-estimated markers.
  - Reusable SeriesChart component; nav links; Meters list rows link to detail.

Tests: MeterMetaTests (Core, +10); DashboardRenderTests extended to assert the
three panel services compute real figures and the new routes render (108 total,
all green). Live-verified in Docker: seed imports 302 readings / 347 consumption
rows; panels render (generation 16,481 kWh, oil 3,967 L) cross-checking the DB.

Claude-Session: https://claude.ai/code/session_01Lz2RqAsnQhetqWNoCDfexK

.dockerignore

@@ -5,7 +5,6 @@
 .git/
 .github/
 docs/
-sampledata/
 tests/
 **/*.user
 **/appsettings.*.Local.json