feat: casan chat optz

packages/casan-harness/scripts/bash/chat-replay.py

@@ -16,6 +16,7 @@ import os
 import subprocess
 import sys
 
+PYTHON_BIN = sys.executable or "/usr/bin/python3"
 
 GENESIS_HASH = "0" * 64
 
@@ -118,7 +119,7 @@ def run_loop_trace(loop_run, cmd: str):
     run_id = loop_run.get("run_id")
     if not run_id:
         return False, "missing_loop_run_id"
-    args = ["python3", LOOP_TRACE, cmd, "--run-id", run_id]
+    args = [PYTHON_BIN, LOOP_TRACE, cmd, "--run-id", run_id]
     if cmd == "replay":
         args += ["--profile", os.environ.get("CASAN_PROFILE", "dev")]
     r = subprocess.run(args, cwd=ROOT, capture_output=True, text=True, env=env)