min_version and max_version accepting weird values

[lucasbalieiro]

potentially related to #2371

this is not explicitly forbidden by the spec, but the parser is accepting min_version > max_version; which is weird;
Maybe is also the case to state the obvious in the spec, but unsure;

test case showing:

diff --git a/sv2/subprotocols/common-messages/src/setup_connection.rs b/sv2/subprotocols/common-messages/src/setup_connection.rs
index 74b46e7f..b4e90fbe 100644
--- a/sv2/subprotocols/common-messages/src/setup_connection.rs
+++ b/sv2/subprotocols/common-messages/src/setup_connection.rs
@@ -522,4 +522,32 @@ mod test {
         setup_conn.set_requires_standard_job();
         assert!(setup_conn.requires_standard_job());
     }
+
+    // Spec 3.6.1: min_version must be <= max_version.
+    // The parser currently accepts min_version > max_version, which is a spec violation.
+    #[test]
+    fn test_setup_connection_accepts_min_version_greater_than_max_version() {
+        // Build raw bytes: protocol=0, min_version=10, max_version=1, flags=0,
+        // empty strings for remaining fields.
+        let mut data = vec![
+            0x00, // protocol: MiningProtocol (0)
+            0x0A, 0x00, // min_version: 10 (LE)
+            0x01, 0x00, // max_version: 1 (LE) — violates spec: min > max
+            0x00, 0x00, 0x00, 0x00, // flags: 0
+            0x00, // endpoint_host: empty
+            0x00, 0x00, // endpoint_port: 0
+            0x00, // vendor: empty
+            0x00, // hardware_version: empty
+            0x00, // firmware: empty
+            0x00, // device_id: empty
+        ];
+        let parsed = SetupConnection::from_bytes(&mut data)
+            .expect("parser should accept min_version > max_version (spec 3.6.1 violation)");
+        assert_eq!(parsed.min_version, 10);
+        assert_eq!(parsed.max_version, 1);
+        assert!(
+            parsed.min_version > parsed.max_version,
+            "min_version should be greater than max_version to demonstrate the bug"
+        );
+    }
 }