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

agent_test/check_frontend_api.py

@@ -0,0 +1,26 @@
+from playwright.sync_api import sync_playwright
+
+url = "https://www.1415243231.top/publish_dishboard"
+
+with sync_playwright() as p:
+    browser = p.chromium.launch(headless=True)
+    page = browser.new_page(viewport={"width": 1280, "height": 720})
+
+    api_calls = []
+    def on_response(r):
+        if '/api/' in r.url:
+            api_calls.append({'status': r.status, 'url': r.url})
+
+    page.on('response', on_response)
+    page.goto(url, timeout=20000, wait_until='networkidle')
+    page.wait_for_timeout(5000)
+
+    print("API calls made by frontend:")
+    for r in api_calls:
+        print(f"  {r['status']} {r['url']}")
+
+    if not api_calls:
+        print("  (no API calls made)")
+        print("\nBody text:", page.inner_text('body')[:200])
+
+    browser.close()