feat(auth,user): login via identifier & update username (#140, #141)

[iamutaki]

API: #140 + #141

#140 — Login via identifier

• LoginValidator: field → (regex, required)
• LoginUserUseCase: lookup by email or fallback username

#141 — Update username

• UpdateMyProfileValidator: field (regex , required)
• UpdateMyProfileUseCase: conflict check + update
• : method

Files

• src/modules/auth/presentation/v1/validators/login.validator.ts
• src/modules/auth/application/use-cases/login-user.use-case.ts
• src/modules/user/presentation/v1/validators/update-my-profile.validator.ts
• src/modules/user/application/use-cases/update-my-profile.use-case.ts
• src/modules/auth/infrastructure/user.repository.impl.ts
• src/modules/auth/domain/repositories/user.repository.ts