fix: Enter key works in amplifier reset on Windows

[Brian Krabach (bkrabach)]

The bug

In amplifier reset, the interactive checklist ignored Enter on Windows — pressing it just re-rendered the menu ("flash") and the reset never confirmed. Only [q] worked. Reported from a real Windows install.

Root cause

amplifier_app_cli/commands/reset_interactive.py, the Windows branch of _get_key(), compared msvcrt.getch() bytes against double-escaped byte literals:

if ch == b"\\xe0":          # 4 chars: backslash x e 0  — never a real keypress
if ch in (b"\\r", b"\\n"):  # 2 chars: backslash r      — never matches Enter
if ch == b"\\x03":          # backslash x 0 3

msvcrt.getch() returns the real byte b"\r" (0x0D) for Enter, which never equals the two-character sequence b"\\r". So Enter fell through to the ch.decode() catch-all, returned "\r", matched no branch in the checklist loop, and the menu simply re-rendered. [q] worked only because "q" is a plain byte needing no escape.

The POSIX branch was already correct (single-escaped "\r", "\x1b"), so POSIX users were never affected — this is Windows-only.

The fix

Single-escape the four literals. Also accept both 0x00 and 0xe0 as the arrow/function-key prefix (Windows uses either) and return "ESC" on an unrecognized prefix, mirroring the POSIX branch. Entirely within the sys.platform == "win32" branch — the POSIX path is byte-identical.

Evidence — native Windows 11, Python 3.14.3

Deterministic teeth test feeding _get_key() the real bytes msvcrt.getch() returns, baseline (main) vs fixed:

[BASELINE] platform=win32
    Enter(b'\r')  -> '\r'      ← not "ENTER": the reported bug
    Up(0xe0 H)    -> ''        ← arrows silently broken too
    VERDICT: Enter confirms + arrows navigate = False

[FIXED] platform=win32
    Enter(b'\r')  -> 'ENTER'
    Space(b' ')   -> ' '
    q             -> 'q'
    Up(0xe0 H)    -> 'UP'
    Up(0x00 H)    -> 'UP'
    VERDICT: Enter confirms + arrows navigate = True

The baseline reproduces the exact symptom (q works, Enter doesn't) and also reveals arrow-key navigation was broken by the same double-escape — invisible because the menu redrew identically.

Limits

One Windows machine, one Python version (3.14.3). No Windows CI leg on this repo yet.