fix: subprocess encoding=utf-8 to prevent GBK stdout crash on Windows - Closes #84

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/run_pipeline.py

@@ -83,7 +83,7 @@ def run_ir_pipeline(parsed_path: str) -> str | None:
         result = subprocess.run(
             [sys.executable, str(script_path)],
             cwd=str(PROJECT_ROOT),
-            capture_output=True, text=True,
+            capture_output=True, text=True, encoding="utf-8",
             env=env,
         )
         if result.returncode != 0:
@@ -111,6 +111,8 @@ def run_acceptance_tests(parsed_json_path: str) -> int:
     print("[3/3] Running QE acceptance tests...")
 
     test_dir = PROJECT_ROOT / "tests" / "acceptance"
+    env = os.environ.copy()
+    env.setdefault("PYTHONIOENCODING", "utf-8")
     result = subprocess.run(
         [
             sys.executable, "-m", "pytest", str(test_dir),
@@ -120,6 +122,8 @@ def run_acceptance_tests(parsed_json_path: str) -> int:
             "--tb=short",
         ],
         cwd=str(PROJECT_ROOT),
+        encoding="utf-8",
+        env=env,
     )
     return result.returncode