fix(windows): add ensure_utf8_streams() for Windows GBK encoding + ConPTY docs

- Add ensure_utf8_streams() in output.py: reconfigures stdout/stderr to UTF-8
  on Windows at CLI startup, fixing emoji UnicodeEncodeError on GBK locales
- Call ensure_utf8_streams() in cli() entry point — one-line fix for all
  output paths (click.echo, rich Console, print)
- Add Windows ConPTY troubleshooting to README (English + Chinese):
  document Git Bash workaround, ConPTY pipe capture issue, and encoding notes

Ref: #29 (issuecomment-4065690862)

twitter_cli/cli.py

@@ -61,6 +61,7 @@ from .output import (
     default_structured_format,
     emit_error,
     emit_structured,
+    ensure_utf8_streams,
     error_payload,
     structured_output_options,
     success_payload,
@@ -303,6 +304,7 @@ def _run_write_command(
 def cli(ctx, verbose, compact):
     # type: (Any, bool, bool) -> None
     """twitter — Twitter/X CLI tool 🐦"""
+    ensure_utf8_streams()
     _setup_logging(verbose)
     ctx.ensure_object(dict)
     ctx.obj["compact"] = compact

twitter_cli/output.py

@@ -14,6 +14,27 @@ _OUTPUT_ENV = "OUTPUT"
 _SCHEMA_VERSION = "1"
 
 
+def ensure_utf8_streams() -> None:
+    """Reconfigure stdout/stderr to use UTF-8 encoding on Windows.
+
+    On Windows with ConPTY disabled (e.g. winpty fallback + PowerShell),
+    the default encoding may be GBK/cp936 which cannot encode emoji.
+    Calling reconfigure(encoding='utf-8') once at startup fixes ALL
+    output paths — click.echo, rich Console, and plain print — without
+    needing per-call wrappers.
+
+    This is a no-op on Unix (already UTF-8) and safe to call multiple times.
+    """
+    if sys.platform != "win32":
+        return
+    for stream in (sys.stdout, sys.stderr):
+        if hasattr(stream, "reconfigure"):
+            try:
+                stream.reconfigure(encoding="utf-8")
+            except Exception:
+                pass  # frozen or non-standard stream, skip
+
+
 def default_structured_format(*, as_json: bool, as_yaml: bool) -> str | None:
     """Resolve explicit flags first, then env override, then TTY default."""
     if as_json and as_yaml:
@@ -126,3 +147,4 @@ def emit_error(
     else:
         click.echo(yaml.safe_dump(payload, allow_unicode=True, sort_keys=False, default_flow_style=False))
     return True
+