feat: implement profile reporting system with admin review

Added comprehensive profile reporting system to allow users to report
inappropriate profiles and admins to review reports.

Features:
- User can report profiles with predefined reasons + custom details
- Duplicate prevention (one pending report per profile per user)
- Rate limiting (5 pending reports maximum per user)
- Admin dashboard to view and filter reports (All, Pending, Reviewed, etc.)
- Admin review modal to update status and add review notes
- Report button on profile page (only visible when viewing others)
- Font Awesome icons for better UI consistency

Database changes:
- New ProfileReport model with ReportReason/ReportStatus enums
- User relations for reports (reportsMade, reportsReceived, reportsReviewed)
- Indices for efficient querying

api/prisma/schema.prisma

@@ -201,10 +201,13 @@ model User {
   isStaff       Boolean        @default(false)
   createdAt     DateTime       @default(now())
   updatedAt     DateTime       @updatedAt
-  comments      Comment[]
-  suggestions   Suggestion[]
-  likes         Like[]
-  refreshTokens RefreshToken[]
+  comments         Comment[]
+  suggestions      Suggestion[]
+  likes            Like[]
+  refreshTokens    RefreshToken[]
+  reportsMade      ProfileReport[] @relation("Reporter")
+  reportsReceived  ProfileReport[] @relation("ReportedUser")
+  reportsReviewed  ProfileReport[] @relation("Reviewer")
 
   @@index([slug], map: "User_slug_key")
 }
@@ -329,3 +332,40 @@ model RefreshToken {
   @@index([userId])
   @@index([expiresAt])
 }
+
+enum ReportReason {
+  INAPPROPRIATE_CONTENT
+  HARASSMENT
+  SPAM
+  IMPERSONATION
+  OFFENSIVE_NAME
+  MALICIOUS_LINKS
+  OTHER
+}
+
+enum ReportStatus {
+  PENDING
+  REVIEWED
+  DISMISSED
+  ACTION_TAKEN
+}
+
+model ProfileReport {
+  id             String        @id @default(auto()) @map("_id") @db.ObjectId
+  reportedUserId String        @db.ObjectId
+  reportedUser   User          @relation("ReportedUser", fields: [reportedUserId], references: [id])
+  reporterId     String        @db.ObjectId
+  reporter       User          @relation("Reporter", fields: [reporterId], references: [id])
+  reason         ReportReason
+  details        String
+  status         ReportStatus  @default(PENDING)
+  reviewedBy     String?       @db.ObjectId
+  reviewer       User?         @relation("Reviewer", fields: [reviewedBy], references: [id])
+  reviewNotes    String?
+  createdAt      DateTime      @default(now())
+  updatedAt      DateTime      @updatedAt
+
+  @@index([reportedUserId])
+  @@index([reporterId])
+  @@index([status])
+}