Add native metaprotocol field

tests/adapters.test.js

@@ -453,3 +453,25 @@ test('multiple input ranges flow FIFO across outputs and protect inscribed fee t
   assert.throws(()=>chain.submitPackage([Tx.encode(burn).hex]),/fee loss/);
   assert.deepEqual(chain.snapshot(),after); assert.ok(after.mempool.length>before.mempool.length);
 });
+
+test("native metaprotocol tag 7 round-trips and overrides metadata.protocol for tracking", () => {
+  const {ins,chain} = setup();
+  const id = ins.inscribe("hello", null, {protocol:"metadata-fallback", note:"kept"}, {metaprotocol:"tea-v1"});
+  const record = chain.transactions.get(id.slice(0,-2));
+  const witness = record.tx.vin.find(i => i.witness?.length === 3).witness;
+  const item = readEnvelope(witness);
+  assert.equal(item.metaprotocol, "tea-v1");
+  assert.deepEqual(item.metadata, {protocol:"metadata-fallback", note:"kept"});
+  const event = new MetadataIndex(chain).events.find(e => e.id === id);
+  assert.equal(event.metaprotocol, "tea-v1");
+  assert.equal(event.protocol, "tea-v1");
+  assert.deepEqual(new MetadataIndex(chain).forProtocol("tea-v1").map(e => e.id), [id]);
+});
+
+test("metadata.protocol remains a fallback when native metaprotocol is absent", () => {
+  const {ins,chain} = setup();
+  const id = ins.inscribe("legacy", null, {protocol:"legacy-protocol"});
+  const event = new MetadataIndex(chain).events.find(e => e.id === id);
+  assert.equal(event.metaprotocol, null);
+  assert.equal(event.protocol, "legacy-protocol");
+});