Windows reports an empty or generic MIME type for .md files, so the
type-first check rejected them with "Разрешены только jpg, png, pdf, md"
even though the extension was allowed — a client hit this while sending
us a vault note.
Extension is now the primary gate; MIME is validated only when the
browser actually sent a meaningful one. Generic types fall back to a
type derived from the extension so the file is served correctly later.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
- Replace non-existent --surface/--surface-muted/--border-strong with actual
design-system tokens (--color-surface, --background, --foreground, --muted)
- Remove tmp/ segment from S3 upload key in question-upload route
- Add auto-scroll to bottom on new message in QuestionThread
- Block Send while file upload is in progress (uploading guard)
- Replace <a> with Next.js <Link> in new question page back-link
- Replace hardcoded #c00 error color with var(--destructive) in both files
- Replace hardcoded #E8E8E0/#F5F5F0 hex backgrounds with CSS tokens
- Add CLOSED status guard in messages POST (returns 409)
- Add extension allowlist check in upload route + text/x-markdown MIME type
- Sanitize files JSON array before DB write
- Add sendQuestionFollowUpEmail helper and use it for student follow-up replies
- Scope email field to staff only in questions list query
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements GET/POST /api/questions, GET /api/questions/[id] with read tracking, POST /api/questions/[id]/messages with email notifications, PATCH /api/questions/[id]/close for staff, and POST /api/student/question-upload for file attachments.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>