test(reference): close numeric-literal coverage gap

tests/reference_numeric_literal_contract.rs

@@ -0,0 +1,59 @@
+//! Public-reference tests for numeric-looking identifiers.
+//!
+//! References made only from numeric characters and their punctuation or signs are rejected.
+//! References that combine letters with numbers remain valid opaque identifiers and keep their
+//! original spelling.
+
+use psychometrics_commons_runtime::participant::{AccountLinkError, ParticipantRecord};
+
+#[test]
+fn numeric_literal_spellings_fail_closed_across_supported_unicode_separators() {
+    let numeric_like_refs = [
+        "123",
+        "+123",
+        "-123",
+        "1.23",
+        "1,234",
+        "1e3",
+        "1E3",
+        "١٢٣",
+        "١٢\u{066B}٣",
+        "١\u{066C}٢٣٤",
+        "１２３",
+        "１２\u{FF0E}３",
+        "１\u{FF0C}２３４",
+    ];
+
+    for invalid_ref in numeric_like_refs {
+        assert_eq!(
+            ParticipantRecord::new_anonymous(invalid_ref, "tenant_alpha", 1),
+            Err(AccountLinkError::InvalidReference),
+            "numeric-like participant reference should fail closed: {invalid_ref:?}",
+        );
+        assert_eq!(
+            ParticipantRecord::new_anonymous("participant_alpha", invalid_ref, 1),
+            Err(AccountLinkError::InvalidReference),
+            "numeric-like tenant reference should fail closed: {invalid_ref:?}",
+        );
+    }
+}
+
+#[test]
+fn numeric_punctuation_remains_valid_inside_opaque_mixed_references() {
+    for valid_ref in [
+        "participant-1",
+        "participant.1",
+        "participant,1",
+        "participant+1",
+        "participant_e1",
+        "participantＥ1",
+    ] {
+        let participant = ParticipantRecord::new_anonymous(valid_ref, "tenant_alpha", 1)
+            .expect("mixed opaque participant references remain valid");
+        assert_eq!(participant.participant_ref(), valid_ref);
+
+        let tenant = ParticipantRecord::new_anonymous("participant_alpha", valid_ref, 1)
+            .expect("mixed opaque tenant references remain valid");
+        assert_eq!(tenant.tenant_ref(), valid_ref);
+    }
+}