feat: add email verification, password reset, and WSDC integration (Phase 1.5)

Backend features:
- AWS SES email service with HTML templates
- Email verification with dual method (link + 6-digit PIN code)
- Password reset workflow with secure tokens
- WSDC API proxy for dancer lookup and auto-fill registration
- Extended User model with verification and WSDC fields
- Email verification middleware for protected routes

Frontend features:
- Two-step registration with WSDC ID lookup
- Password strength indicator component
- Email verification page with code input
- Password reset flow (request + reset pages)
- Verification banner for unverified users
- Updated authentication context and API service

Testing:
- 65 unit tests with 100% coverage of new features
- Tests for auth utils, email service, WSDC controller, and middleware
- Integration tests for full authentication flows
- Comprehensive mocking of AWS SES and external APIs

Database:
- Migration: add WSDC fields (firstName, lastName, wsdcId)
- Migration: add email verification fields (token, code, expiry)
- Migration: add password reset fields (token, expiry)

Documentation:
- Complete Phase 1.5 documentation
- Test suite documentation and best practices
- Updated session context with new features

backend/prisma/schema.prisma

@@ -12,20 +12,36 @@ datasource db {
 
 // Users table
 model User {
-  id            Int       @id @default(autoincrement())
-  username      String    @unique @db.VarChar(50)
-  email         String    @unique @db.VarChar(255)
-  passwordHash  String    @map("password_hash") @db.VarChar(255)
-  avatar        String?   @db.VarChar(255)
-  createdAt     DateTime  @default(now()) @map("created_at")
-  updatedAt     DateTime  @updatedAt @map("updated_at")
+  id                      Int       @id @default(autoincrement())
+  username                String    @unique @db.VarChar(50)
+  email                   String    @unique @db.VarChar(255)
+  passwordHash            String    @map("password_hash") @db.VarChar(255)
+
+  // WSDC Integration (Phase 1.5)
+  firstName               String?   @map("first_name") @db.VarChar(100)
+  lastName                String?   @map("last_name") @db.VarChar(100)
+  wsdcId                  String?   @unique @map("wsdc_id") @db.VarChar(20)
+
+  // Email Verification (Phase 1.5)
+  emailVerified           Boolean   @default(false) @map("email_verified")
+  verificationToken       String?   @unique @map("verification_token") @db.VarChar(255)
+  verificationCode        String?   @map("verification_code") @db.VarChar(6)
+  verificationTokenExpiry DateTime? @map("verification_token_expiry")
+
+  // Password Reset (Phase 1.5)
+  resetToken              String?   @unique @map("reset_token") @db.VarChar(255)
+  resetTokenExpiry        DateTime? @map("reset_token_expiry")
+
+  avatar                  String?   @db.VarChar(255)
+  createdAt               DateTime  @default(now()) @map("created_at")
+  updatedAt               DateTime  @updatedAt @map("updated_at")
 
   // Relations
-  messages      Message[]
-  matchesAsUser1 Match[]  @relation("MatchUser1")
-  matchesAsUser2 Match[]  @relation("MatchUser2")
-  ratingsGiven  Rating[]  @relation("RaterRatings")
-  ratingsReceived Rating[] @relation("RatedRatings")
+  messages                Message[]
+  matchesAsUser1          Match[]  @relation("MatchUser1")
+  matchesAsUser2          Match[]  @relation("MatchUser2")
+  ratingsGiven            Rating[]  @relation("RaterRatings")
+  ratingsReceived         Rating[] @relation("RatedRatings")
 
   @@map("users")
 }