refactor: replace chromedp with browser native print for PDF export

Remove chromedp dependency, use window.print() instead. Docker image no longer needs Chromium (~200MB smaller).

- Delete services/pdf.go and templates/reports/review.html

- Remove PDF API route POST /api/repos/:id/review/pdf

- Add @media print CSS to review page

- Remove chromium from Dockerfile

main.go

@@ -124,7 +124,7 @@ func main() {
 	r.GET("/api/repos/:id/review/analyses/:aid", authMw, review.GetReview)
 	r.POST("/api/repos/:id/review/notes", authMw, review.SaveNotes)
 	r.GET("/api/repos/:id/review/notes", authMw, review.GetNotes)
-	r.POST("/api/repos/:id/review/pdf", authMw, review.GeneratePDF)
+
 
 	// Graceful shutdown with signal handling
 	srv := &http.Server{