The Findings and SBOM pages populated their target dropdown from the legacy
`repositories` collection, so onboarded targets never appeared and their
findings/SBOM couldn't be filtered by name (the data was there, keyed by the
target id). Point both dropdowns at `onboarded_targets` via `fetch_targets`.
Also refresh `OnboardedTarget.findings_count` at the end of `run_target`: the
shared pipeline (Stage 7) increments the legacy `repositories` doc, which the
unified path has none of, so the Targets page always showed 0. Set the accurate
total (count of findings keyed by the target id) on the target itself.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>