feat(messaging-streams): manually deepen all six stream utility modules

- chunker: framed seq chunks, reassemble, setChunkSize
- multiplex: closeAll, getStream, per-stream byte counters
- backpressure: low/high water marks, bufferedBytes
- tee: branchBytes, removeBranch, depth guard
- transform: pipeTo and outbound backpressure
- resume-token: labeled checkpoints, clearTokens, bytesFromOffset
- Update category README and chunker tests

Co-authored-by: Cursor <[email protected]>

messaging-streams/hyper-p2p-stream-chunker/test/test.js

@@ -8,7 +8,16 @@ test('split chunks', async (t) => {
   const m = new HyperP2PStreamChunker({ chunkSize: 4 })
   const parts = m.push(require('b4a').from('abcdefgh'))
   t.is(parts.length, 2)
-  t.is(parts[0].length, 4)
+  t.is(parts[0].data.length, 4)
+  t.is(parts[0].seq, 0)
+  await m.close()
+})
+
+test('reassemble', async (t) => {
+  const m = new HyperP2PStreamChunker({ chunkSize: 3 })
+  m.push(require('b4a').from('hello'))
+  m.flush()
+  t.is(m.reassemble().toString(), 'hello')
   await m.close()
 })