fix: clean up church-matcher types and add HK OSM bounding box

- Remove discovermassId/buscarmisasNetworkId from findDuplicateChurch match
  passes (importers now do their own pre-check dedup); restore as optional
  fields on ExistingChurch to keep type/runtime in sync
- Add HK bounding box to COUNTRY_BOUNDING_BOXES; fix silent 0-result
  fallback when country query returns empty from mirror server
- discovermass importer: add --limit flag and skip-already-imported
  pre-check using importedSlugs set
- Import scripts: remove discovermassId from ExistingChurch select/stubs
  (field not needed in shared matcher context)
- Schema: reorder discovermassId/kerknetId/gottesdienstzeitenId fields

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -22,7 +22,6 @@
     "scrape:diocese": "tsx scripts/scrape-diocese-directory.ts",
     "setup:diocese": "tsx scripts/setup-diocese.ts",
     "import:gcatholic": "tsx scripts/import-gcatholic.ts",
-    "import:buscarmisas-network": "tsx scripts/import-buscarmisas-network.ts",
     "import:orarimesse": "tsx scripts/import-orarimesse.ts",
     "import:mass-schedules-ph": "tsx scripts/import-mass-schedules-ph.ts",
     "import:philmass": "tsx scripts/import-philmass.ts",