Read the real PK from the wrapped table instead of re-querying DbSchema

Addresses PR feedback: the wrapped SimpleTable already holds the source SchemaTableInfo, so read the real PK via getRealTable() (the same idiom ContainerScopedTable.init() uses) rather than resolving the table again through _dbSchema.getTable().

Claude-Session: https://claude.ai/code/session_01YJwkmACfqMmYiAX15YbU1D

Author: labkey-martyp

ehr/src/org/labkey/ehr/query/EHRLookupsUserSchema.java

@@ -219,7 +219,9 @@ else if (EHRSchema.TABLE_LOOKUP_SETS.equalsIgnoreCase(name))
             // (e.g. project_types) get CustomPermissionsTable instead: the PK constraint already enforces uniqueness,
             // and container-scoping such a table made its key column non-insertable in the UI.
             String pkColName = getPkColName(ti);
-            List<String> realPk = _dbSchema.getTable(name).getPkColumnNames();
+            List<String> realPk = ti instanceof FilteredTable<?> ft
+                    ? ft.getRealTable().getPkColumnNames()
+                    : _dbSchema.getTable(name).getPkColumnNames();
             boolean singleColumnPks = pkColName != null && realPk.size() == 1;
             boolean realPkMatchesPseudoPk = singleColumnPks && realPk.get(0).equalsIgnoreCase(pkColName);