Adds the four missing audio extensions to ShareModal.vue's extension-to-
MIME map (m4a->audio/mp4, aac->audio/aac, opus->audio/opus, wma->audio/
x-ms-wma), extracted to an exported module-scope SHARE_MIME_MAP so it's
directly fixture-testable (useFileType.test.ts convention). All three
maps agree that these eight extensions are audio/*: SHARE_MIME_MAP,
archyContentAdapter.ts's classifyByMime (13-06), and content.rs's
auto-filing check, which is prefix-only (mime_type.starts_with("audio/"))
so any correct audio/* value here already satisfies it. Existing four
entries (mp3/flac/ogg/wav) and the generic-fallback behavior for unknown
extensions are unchanged. Whole neode-ui suite green (924/924).
archipelago
abe77ebe7e