fix(mac-chat): stop [stream] progress lines interleaving with the answer (#153)

The per-block '[stream] blk=.. t=..s' lines went to stderr while the answer
delta went to stdout; on a shared terminal they interleaved INTO the text
(在计算机[stream] blk=1...). Emit the timing line ONLY on the non-interactive
(scripted/bridge) path; the interactive CLI now streams ONLY the clean answer
delta. Add --chat-stream-stdout so a non-tty bridge run can capture the exact
clean live format for validation.

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: FluffyAIcode <FluffyAIcode@users.noreply.github.com>

Author: FluffyAIcode

inference_engine/bridge/manifest.py

@@ -767,7 +767,8 @@ def _harness_preset(
                     "--s5-exact-full-attn", "--fused-specdecode", "--force-f-theta",
                     "--sink-size", "4", "--window-size", "64", "--block-size", "4",
                     "--max-new-tokens", "{max_new_tokens}", "--ignore-turn-stop",
-                    "--chat", "--chat-scripted", "根据pow的机制，给出完整的c代码实现",
+                    "--chat", "--chat-stream-stdout",
+                    "--chat-scripted", "根据pow的机制，给出完整的c代码实现",
                     "--output", "results/research/chat_stream_probe_2815.json",
                 ),
             ),

scripts/research/k3_integrated_niah_eval_mac.py

@@ -180,6 +180,11 @@ def parse_args() -> argparse.Namespace:
     ap.add_argument("--chat-scripted", default=None,
                     help="Non-interactive chat: '||'-separated user turns "
                          "(for Mac-bridge verification); writes a transcript.")
+    ap.add_argument("--chat-stream-stdout", action="store_true",
+                    help="In scripted chat, stream the clean answer delta to "
+                         "stdout (as the interactive CLI does) instead of the "
+                         "per-block [stream] timing lines — lets a non-tty bridge "
+                         "run capture the exact live output format.")
     ap.add_argument("--chat-native-ref", action="store_true",
                     help="DIAGNOSTIC opt-in: before each chat turn, also run a "
                          "plain NATIVE greedy AR decode of the SAME prompt for "
@@ -870,15 +875,21 @@ def cb(toks: List[int]) -> None:
                     except TypeError:
                         txt = tokenizer.decode(toks)
                     if to_stdout:
+                        # Interactive: emit ONLY the clean answer delta to stdout.
+                        # (No per-block progress line here — stderr would interleave
+                        # with the streamed text in the terminal and mangle it.)
                         delta = txt[st["chars"]:]
                         if delta:
                             sys.stdout.write(delta)
                             sys.stdout.flush()
                             st["chars"] = len(txt)
-                    sys.stderr.write(
-                        f"[stream] blk={st['blk']} tok={len(toks)} "
-                        f"t={time.perf_counter() - st['t0']:.1f}s\n")
-                    sys.stderr.flush()
+                    else:
+                        # Non-interactive (bridge/scripted): timing-only progress to
+                        # stderr (proves streaming / liveness in the captured log).
+                        sys.stderr.write(
+                            f"[stream] blk={st['blk']} tok={len(toks)} "
+                            f"t={time.perf_counter() - st['t0']:.1f}s\n")
+                        sys.stderr.flush()
                 return cb
 
             print(f"[chat] FULL fused engine: verifier={args.verifier_path} "
@@ -893,8 +904,14 @@ def cb(toks: List[int]) -> None:
                 transcript = []
                 for u in turns:
                     history.append({"role": "user", "content": u})
-                    res = _gen_turn(_encode_chat(history),
-                                    on_commit=_make_stream_cb(to_stdout=False))
+                    if args.chat_stream_stdout:
+                        sys.stdout.write(f"\ngemma-4 [{u[:24]}]> ")
+                        sys.stdout.flush()
+                    res = _gen_turn(_encode_chat(history), on_commit=_make_stream_cb(
+                        to_stdout=args.chat_stream_stdout))
+                    if args.chat_stream_stdout:
+                        sys.stdout.write("\n")
+                        sys.stdout.flush()
                     history.append({"role": "assistant", "content": res["text"]})
                     tps = (res["decode_tokens"] / res["decode_s"]
                            if res["decode_s"] > 0 else 0.0)