fix(review): address Copilot follow-up on sanitizer and file decode errors

Consume multi-byte non-CSI ESC sequences during ANSI sanitization and handle UnicodeDecodeError for `hermes send --file` so review findings are resolved without regressions.

tests/hermes_cli/test_send_cmd.py

@@ -173,6 +173,19 @@ def test_file_not_found_is_usage_error(fake_tool, capsys, monkeypatch):
     assert "cannot read" in err.lower()
 
 
+def test_file_decode_error_is_usage_error(fake_tool, capsys, monkeypatch, tmp_path):
+    monkeypatch.setattr("sys.stdin.isatty", lambda: True)
+    bad = tmp_path / "bad-bytes.bin"
+    bad.write_bytes(b"\xff\xfe\x00")
+
+    args = _parse(["--to", "telegram", "--file", str(bad)])
+    with pytest.raises(SystemExit) as exc:
+        send_cmd.cmd_send(args)
+    assert exc.value.code == 2
+    err = capsys.readouterr().err
+    assert "cannot read" in err.lower()
+
+
 def test_tool_error_returns_failure_exit(monkeypatch, capsys):
     import sys as _sys
     import types as _types