Drop the CVE metrics the artifacts cannot answer

Time to exploit, CVE volume trends, CWE abstraction level and CWE
relationships need exploitation history, earlier scans or the CWE catalog,
none of which the VDR carries, so they only ever showed <xxx>.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

report_generator/context.py

@@ -345,13 +345,11 @@ def _metric_cards(dependencies: dict[str, Any]) -> list[dict[str, Any]]:
         },
         {
             "title": "Temporal",
-            "note": "Published dates and vulnerability age are calculated from the advisory timestamps. Time-to-exploit and volume trends require historical exploitation or scan data that this export does not contain.",
+            "note": "Published dates and vulnerability age are calculated from the advisory timestamps.",
             "rows": [
                 _fact("Newest published", _published(published.get("newest"))),
                 _fact("Mean vulnerability age", _days(published.get("mean_days"))),
                 _fact("Median vulnerability age", _days(published.get("median_days"))),
-                _fact("Time to exploit", temporal.get("time_to_exploit_days")),
-                _fact("CVE volume trends", temporal.get("cve_volume_trends")),
             ],
         },
         {
@@ -361,8 +359,6 @@ def _metric_cards(dependencies: dict[str, Any]) -> list[dict[str, Any]]:
                 _fact("Affected dependencies", surface.get("products")),
                 _fact("Potential remedies", _remedy(upgrades)),
                 _fact("CWE coverage", taxonomy.get("coverage")),
-                _fact("CWE abstraction level", taxonomy.get("abstraction_level")),
-                _fact("CWE relationships", taxonomy.get("relationships")),
             ],
         },
     ]