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/migrations/20251113151534_add_wsdc_and_email_verification/migration.sql

@@ -0,0 +1,23 @@
+-- AlterTable: Add WSDC Integration fields
+ALTER TABLE "users" ADD COLUMN "first_name" VARCHAR(100),
+ADD COLUMN "last_name" VARCHAR(100),
+ADD COLUMN "wsdc_id" VARCHAR(20);
+
+-- AlterTable: Add Email Verification fields
+ALTER TABLE "users" ADD COLUMN "email_verified" BOOLEAN NOT NULL DEFAULT false,
+ADD COLUMN "verification_token" VARCHAR(255),
+ADD COLUMN "verification_code" VARCHAR(6),
+ADD COLUMN "verification_token_expiry" TIMESTAMP(3);
+
+-- AlterTable: Add Password Reset fields
+ALTER TABLE "users" ADD COLUMN "reset_token" VARCHAR(255),
+ADD COLUMN "reset_token_expiry" TIMESTAMP(3);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "users_wsdc_id_key" ON "users"("wsdc_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "users_verification_token_key" ON "users"("verification_token");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "users_reset_token_key" ON "users"("reset_token");