Under start.bat the server's stdout/stderr are pipes into PowerShell's
Tee-Object, so Python encodes with the ANSI code page instead of the
wide console API. cp1251 (Russian Windows) cannot encode the banner's
box-drawing rule (U+2500), and that print killed the server with
UnicodeEncodeError before it could listen.
- _guard_console_streams() (the first statement of main()) sets
errors="replace" on both streams: an unencodable character prints as
'?' and can never raise.
- _console_rule() picks the widest banner rule its stream can encode -
U+2500 where the code page has it (utf-8, cp437), ASCII dashes
otherwise (cp1251, ascii).
- The seven text-layer trace strings are ASCII now: the APDU arrows
(U+2192) and the INIT/CAP-COMPAT em dashes (U+2014 - cp437 cannot
encode them either), so the traces stay readable on any code page.
The raw os.write paths (_log_stdout, the APDU tracer) bypass the text
layer, cannot crash, and were left as-is.
Tests: tests/test_console_encoding.py - the strict-cp1251 control, the
rule's fallback/pretty cases, the guarded banner+traces, a stream
without reconfigure, the main() source pin, and an AST pin that no
print/stdout/stderr literal in the package is non-ASCII.
tests/test_startup_cardless.py's CARDLESS_LINE follows the new ASCII
line.
Verified with PYTHONUNBUFFERED=1 PYTHONIOENCODING=cp1251: the pre-fix
code died at the banner, the fixed code reaches the listening banner
and serves a command (CMD: -> OK, no encode errors).
930 frontend + 952 Python; sw cache simple-v453.
