v3.30.3: the Windows console encoding guard

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.

frontend/index.html

@@ -1932,7 +1932,7 @@
 // ===== Version =====
 // Single source of truth for the PWA version: shown in the header and used
 // by the server version check in pysimConnect().
-const SIMPLE_VERSION = '3.30.2';
+const SIMPLE_VERSION = '3.30.3';
 document.getElementById('app-version').textContent = 'v' + SIMPLE_VERSION;
 
 // ===== view history (the browser Back/Forward buttons) =====