Phase 2+5: lab submissions and student lab flow
- progress: submissions table+V4; SubmissionService (deadline-gated submit,
unlimited resubmits, per-student history, zip download); files on disk
data/submissions/{student}/{lab}/{seq}/
- student API: POST submit (multipart), GET me submissions, download; admin
GET lab submissions + admin download (zip pack)
- progress enrich(): labId in MeAssignment; web DTO aligned
- web: /student dashboard (avg/best/worst cards), /student/labs cards,
/student/labs/{id}: condition md, variant block, submit form, history;
'Лабораторные' link in nav for students
- admin: submissions column on lab assignment table + download link
- fixed long-standing template bug: broken @{} expression (missing }) in
admin/lab and student/lab
Vladislav Kopnin
e1da254599