Initial fullstack project setup with Next.js 15, Gin, PostgreSQL and Docker Compose

- Frontend: Next.js 15 (App Router), Auth.js v5, shadcn/ui, MagicUI
- Backend: Go + Gin + GORM with layered architecture
- Auth: Local credentials login with optional Keycloak OAuth binding
- Admin: RBAC user management for admin role
- Dev: Docker Compose with hot reload for both frontend and backend
- Docker: 3-service orchestration (frontend, backend, postgres)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/Dockerfile

@@ -0,0 +1,27 @@
+FROM golang:1.25-alpine AS builder
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o server ./cmd/api/main.go
+
+FROM golang:1.25-alpine AS dev
+
+RUN go install github.com/air-verse/air@latest
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+
+EXPOSE 8080
+CMD ["air", "-c", ".air.toml"]
+
+FROM alpine:latest AS production
+
+WORKDIR /app
+COPY --from=builder /app/server .
+
+EXPOSE 8080
+CMD ["./server"]