fix: evaluation report P0/P1/P2 fixes, remove Docker, add upload UI

Backend:
- Add NotFoundException + BusinessException, return correct HTTP status (404/400)
- Add @Index on reports.project_id and reports.upload_time
- Add fileSize column to reports, populate on upload, return in DTO
- Cascade delete: deleting project now removes all reports (DB + files + PDFs)
- Delete report: also clean up pre-rendered PDF
- File upload MIME validation (extension + Content-Type)
- Remove duplicate @ExceptionHandler from ReportController
- Switch from System.err to SLF4J logger
- Handle MethodArgumentNotValid, MissingServletRequestPart, etc.

Frontend:
- Remove all Docker files (project uses 宝塔 panel deployment)
- Upgrade axios 1.6.8 -> 1.7.7 (CVE-2024-39338)
- Remove unused @vue-office/pptx + vue-demi (see CHANGELOG for rationale)
- Fix vite proxy port 37821 -> 30081
- Remove mock data fallback in production
- Add upload report UI (button + modal in ProjectDetail)
- Add create project UI (button + modal in ProjectList)
- Add filename search box in ProjectDetail
- New useApi methods: createProject, uploadReport, deleteProject, deleteReport
- FilePreview/ReportCard: show fileSize (was undefined before)

Docs:
- Add README.md (overview, quick start, structure)
- Add CHANGELOG.md (full change log + pptx removal rationale)
- Include EVALUATION_REPORT.md and blog-vibe-coding.md

Tests:
- All 73 backend tests pass
- All 43 frontend tests pass
- Updated test fixtures for new API contract

package.json

@@ -13,11 +13,9 @@
     "test:e2e:ui": "playwright test --ui"
   },
   "dependencies": {
-    "@vue-office/pptx": "^1.0.1",
-    "axios": "^1.6.8",
+    "axios": "^1.7.7",
     "marked": "^12.0.0",
     "vue": "^3.4.21",
-    "vue-demi": "^0.14.6",
     "vue-router": "^4.3.0"
   },
   "devDependencies": {