add VC and VertexCover as aliases for DecisionMinimumVertexCover

Closes #1050 — users can now refer to the decision vertex cover problem
as "VC", "VertexCover", or "DMVC" (legacy). The internal registered name
remains DecisionMinimumVertexCover to avoid breaking the proc macro name
extraction in #[reduction].

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: isPANN

problemreductions-cli/src/problem_name.rs

@@ -310,6 +310,8 @@ mod tests {
             "BiconnectivityAugmentation"
         );
         assert_eq!(resolve_alias("DMVC"), "DecisionMinimumVertexCover");
+        assert_eq!(resolve_alias("VC"), "DecisionMinimumVertexCover");
+        assert_eq!(resolve_alias("VertexCover"), "DecisionMinimumVertexCover");
         // Pass-through for full names
         assert_eq!(
             resolve_alias("MaximumIndependentSet"),

src/models/graph/minimum_vertex_cover.rs

@@ -186,7 +186,7 @@ crate::register_decision_variant!(
     MinimumVertexCover<SimpleGraph, i32>,
     "DecisionMinimumVertexCover",
     "1.1996^num_vertices",
-    &["DMVC"],
+    &["DMVC", "VC", "VertexCover"],
     "Decision version: does a vertex cover of cost <= bound exist?",
     dims: [
         VariantDimension::new("graph", "SimpleGraph", &["SimpleGraph"]),

src/unit_tests/registry/schema.rs

@@ -95,7 +95,7 @@ fn test_decision_problem_schema_entries_registered() {
         .iter()
         .find(|entry| entry.name == "DecisionMinimumVertexCover")
         .expect("DecisionMinimumVertexCover schema should be registered");
-    assert_eq!(mvc.aliases, ["DMVC"]);
+    assert_eq!(mvc.aliases, ["DMVC", "VC", "VertexCover"]);
     assert!(mvc.fields.iter().any(|field| field.name == "bound"));
     assert_eq!(mvc.dimensions.len(), 2);
     assert!(