Architecture name lookup in `parse_config` was a case-sensitive StrEnum
lookup. Since the enum carries both lowercase `arm64` (macOS/Android) and
uppercase `ARM64` (Windows), `parse_config("arm64", "windows")` silently
returned the macOS member and later failed with a confusing "Invalid archs
option" error, while lowercase `amd64` failed to parse at all.
Resolve names case-insensitively, preferring a member valid for the target
platform before falling back to any case-insensitive match (which keeps the
clear ConfigurationError for genuinely invalid names).
Closes#2373
Assisted-by: ClaudeCode:claude-opus-4.8
Henry Schreiner
dc30bfb527