feat(07-04): wire keyhunter import command with dedup and DB persist
- Replace import stub with cmd/import.go dispatching to pkg/importer
(trufflehog, gitleaks, gitleaks-csv) via --format flag
- Reuse openDBWithKey helper so encryption + path resolution match scan/keys
- engineToStorage converts engine.Finding -> storage.Finding (Source -> SourcePath)
- Add pkg/storage.FindingExistsByKey for idempotent cross-import dedup
keyed on (provider, masked key, source path, line number)
- cmd/import_test.go: selector table, field conversion, end-to-end trufflehog
import with re-run duplicate assertion, unknown-format + missing-file errors
- pkg/storage queries_test: FindingExistsByKey hit and four miss cases
Delivers IMP-01/02/03 end-to-end.
9dbb0b87d4