aura data coverage <SYMBOL> prints the archive's monthly file-index
coverage: a span line (first..last present month) and either an explicit
'no gaps' line or one 'missing: YYYY-MM..YYYY-MM' line per interior
contiguous hole. The Copper failure mode — a campaign aborting mid-run
because a first/last-bounds check passed while the window start had no
data — is now visible before any run (the real archive reports
'Copper missing: 2017-04..2019-09'). An unknown symbol (no archive
files) refuses on stderr with exit 1; informational absence stays
prose + exit 0 per the verb corpus convention.
Mechanics: list_m1_months goes pub in aura-ingest (archive_extent
deliberately walks past gaps and cannot report them); a new two-level
'aura data' clap namespace follows the Nodes precedent; the archive
root resolves through the normal project path (paths.data override,
data-server default otherwise). Pure report fn with unit tests for the
refusal, the gapless span, and the collapsed-range shape; the headline
e2e runs hostless over a new gapped synthetic-archive fixture.
refs #264 (cut 2, aura data list, follows separately)
claude
529a8af0d6