Add bcrypt user file auth, JWT middleware on all write routes, Pinia
authStore with localStorage persistence, login view with redirect
support, and v-if guards on all CRUD controls and admin nav link.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
golang-migrate, pgx/v5, and echo/v4 are all imported directly;
go mod tidy correctly marks them as direct dependencies.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>