fix(catalog,tests): address PR #196 review (Copilot)

Three valid review findings, all verified before acting:

- test_plugins_cli.py: synthetic catalog fixtures used data_source "Custom",
  which now violates the tightened catalog_entry.schema.json enum. This was
  not merely cosmetic: in test_validate_rejects_duplicate_accession_within_catalog
  the per-entry schema failure short-circuited (validate_cmd `continue`s on a
  schema error) so the duplicate-accession branch was never reached -- the test
  passed for the wrong reason. Use a valid enum value ("ClinGen"); verified the
  dedup branch is exercised again ("duplicate accession within catalog: DUP").
- test_unified_registry_per_plugin.py: same "Custom" -> "ClinGen" in the two
  fake-entry fixtures, to keep examples consistent with the schema (the registry
  loader doesn't schema-validate, so behavior is unchanged).
- gwas_catalog/catalog/datasets.json: the file description claimed "pinned
  content: e115 / r2026-04-27" while the url is the rolling releases/latest/
  endpoint. Reworded to clarify the url is the latest-release endpoint (may
  resolve to a newer release) and that the built-from release lives in accession.

Verified: full fast suite 1004 passed, 0 failed, 4 skipped.

Author: enriquea

hvantk/skills/gwas_catalog/catalog/datasets.json

@@ -28,7 +28,7 @@
         "format": "tsv",
         "size_bytes": 556245182,
         "url": "https://ftp.ebi.ac.uk/pub/databases/gwas/releases/latest/gwas-catalog-associations-full.zip",
-        "description": "Full associations TSV (v1.0, 34 columns), unzipped from the EBI GWAS Catalog latest-release archive (pinned content: e115 / r2026-04-27). The legacy api/search/downloads/full endpoint has been retired (404); this FTP archive is the URL the drift probe fingerprints."
+        "description": "Full associations TSV (v1.0, 34 columns), unzipped from the EBI GWAS Catalog full-associations archive. The `url` is the rolling latest-release endpoint (the same one the drift probe fingerprints) and may resolve to a newer release over time; the specific release this entry was built from is recorded in `accession` (e115 / r2026-04-27). The legacy api/search/downloads/full endpoint has been retired (404)."
       }
     ]
   }

hvantk/tests/test_plugins_cli.py

@@ -94,7 +94,7 @@ def test_validate_rejects_catalog_entry_missing_required_field(tmp_path):
     from hvantk.tools.plugins.plugins_cli import plugins_group
     (tmp_path / "catalog").mkdir()
     (tmp_path / "catalog" / "datasets.json").write_text(
-        '[{"title": "x", "description": "d", "data_source": "Custom", '
+        '[{"title": "x", "description": "d", "data_source": "ClinGen", '
         '"organism": "Homo sapiens", "files": []}]'  # missing "accession"
     )
     (tmp_path / "plugin.yaml").write_text(
@@ -112,7 +112,7 @@ def test_validate_rejects_duplicate_accession_within_catalog(tmp_path):
     from hvantk.tools.plugins.plugins_cli import plugins_group
     (tmp_path / "catalog").mkdir()
     entry = ('{"accession": "DUP", "title": "x", "description": "d", '
-             '"data_source": "Custom", "organism": "Homo sapiens", "files": []}')
+             '"data_source": "ClinGen", "organism": "Homo sapiens", "files": []}')
     (tmp_path / "catalog" / "datasets.json").write_text(f"[{entry}, {entry}]")
     (tmp_path / "plugin.yaml").write_text(
         "api_version: 2\nname: tmp-plug\nversion: 0.1.0\n"

hvantk/tests/test_unified_registry_per_plugin.py

@@ -102,7 +102,7 @@ def __init__(self, name, catalog_path):
     def _entry(acc):
         return {
             "accession": acc, "title": acc, "description": "x",
-            "data_source": "Custom", "organism": "Homo sapiens", "files": [],
+            "data_source": "ClinGen", "organism": "Homo sapiens", "files": [],
         }
 
     cat_a = tmp_path / "a.json"; cat_a.write_text(json.dumps([_entry("DUP")]))
@@ -137,7 +137,7 @@ def __init__(self, name, catalog_path, domain):
     cat.write_text(
         json.dumps([{
             "accession": "X1", "title": "X1", "description": "x",
-            "data_source": "Custom", "organism": "Homo sapiens", "files": [],
+            "data_source": "ClinGen", "organism": "Homo sapiens", "files": [],
         }])
     )