Author dataAvailability and dependencies for one real pathway

[jacobvjk]

Part of #860; blocks observing #870 and half of #872.

Problem

No pathway in src/data/ carries a dataAvailability field at all, and every one has dependencies: []:

ACE-ATS-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
ACE-BAS-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
ACE-CNS-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
ACE-RAS-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
IEA-APS-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
IEA-NZE-2024     dataAvailability=ABSENT   byMetric rows=0   dependencies=0
IEA-STEPS-2024   dataAvailability=ABSENT   byMetric rows=0   dependencies=0

(Those seven are the only pathways currently loadable — the other 49 files are still schema v1 and skipped.)

So two of the three surfaces built in #936 and scoped in #946 render only their empty states in the running app:

• the Data Availability table (dataAvailability field + download/link table #870) — its rows, its conditional Sector / Geography scope columns, its scope filtering, its filtered-empty copy
• the Dependencies table — its rows, its evidence pills, its sector filtering

Both are covered by component tests against fixtures, and testdata/valid/pathwayMetadata_v2_full.json exercises the schema. But nobody has seen either table with real content, so design problems that only appear with real values — column widths, long authored prose, how many rows a real pathway generates — are undiscoverable.

Suggestion

Author dataAvailability (including a few byMetric rows) and dependencies for one real pathway, ideally a multi-sector, multi-geography one so the conditional columns and the scope filtering actually engage. IEA-APS-2024 is the natural candidate: 12 sectors, 15 geography tokens.

testdata/valid/pathwayMetadata_v2_full.json is a working shape to copy from, and npm run schema:check validates the result.

Worth noting while authoring

• Row uniqueness is (metricName, sector, sectorSegment, geography), enforced by scripts/schema-check-files.ts.
• byMetric[].geography takes the same scope token as keyFeatures — so it participates in the detail page's geography filter.
• sectorSegment values changed in Feat/UI tabs #936: Storage → Energy storage, plus a new Fuel extraction and processing.
• metricName must be one of the pathway's own metric values and a metric of its sector.