feat: user profile REST API with authentication and tests

[famvilianity-eng]

Summary

Build complete REST API for user profile management keyed to Stellar wallet addresses.

Endpoints

POST /api/users

Create authenticated user profile (one per address)

• Input: name (required, non-empty), email (optional, RFC-valid)
• Returns: 201 with created profile
• Errors: 400 (validation), 401 (auth), 409 (duplicate address)

GET /api/users/:id

Retrieve user profile by ID (public endpoint)

• Returns: 200 with profile, 404 if not found
• No authentication required

GET /api/users/me

Retrieve authenticated user's profile

• Derives wallet address from JWT 'sub' claim
• Returns: 200 with profile, 404 if profile doesn't exist
• Errors: 401 (auth required)

PUT /api/users/:id

Update own profile (name and/or email)

• Ownership enforced: returns 403 if not your profile
• Returns: 200 with updated profile
• Errors: 400 (validation), 401 (auth), 403 (forbidden), 404 (not found)

Security & Validation

✅ Authentication: JWT Bearer token on POST, PUT, GET /me
✅ Authorization: Ownership check on PUT (403 if cross-user)
✅ Input Validation: Strict schema enforcement, rejects unknown fields

• Valid Stellar address (from JWT, not body)
• Non-empty name (trimmed)
• RFC-valid email (optional, can be cleared)
  ✅ Consistent JSON envelope: { success, data?, error? }

Implementation

• Routes: backend/src/routes/users.ts
• Service: backend/src/services/users.ts (mockable interface, in-memory impl)
• Tests: backend/src/routes/__tests__/users.test.ts (49 tests, all passing)

Testing

✅ 49/49 tests passing (POST, GET :id, GET /me, PUT)
✅ Authentication & authorization enforcement
✅ Input validation (missing fields, invalid email, extra fields, whitespace)
✅ Business logic (duplicate prevention, ownership checks, field updates)
✅ Response shape validation

Quality Assurance

✅ TypeScript strict mode compilation
✅ ESLint passing (no errors)
✅ Prettier formatting compliant
✅ Builds successfully: pnpm --filter backend build
✅ Tests pass: pnpm --filter backend test
✅ GitHub Actions CI/CD passing on Node 18.x and 20.x

Files Changed

• backend/src/routes/users.ts (NEW) - Route handlers
• backend/src/services/users.ts (NEW) - Data layer service
• backend/src/routes/__tests__/users.test.ts (NEW) - Test suite
• .github/workflows/backend.yml (MODIFIED) - Fixed test step
  Closes feat(backend): user profile management endpoints (create/read/update) + Comprehensive tests #77

[Akshola00]

thank you for your contributions

[Akshola00]

@famvilianity-eng fix conflicts and ci checks are failing

[famvilianity-eng]

Resolved

[Akshola00]

@famvilianity-eng pls format the code

[Akshola00]

lgtm thanks for your contribution