feat(server): initialize project skeleton with db and api setup

Establish the foundational structure for the ez-api server.

Key changes include:
- Set up main entry point with graceful shutdown and Gin router
- Configure database connections for PostgreSQL (GORM) and Redis
- Define core data models (User, Provider, Key, Model)
- Implement configuration loading and basic key creation handler
- Add Dockerfile for multi-stage builds and .gitignore

Dockerfile

@@ -0,0 +1,19 @@
+FROM golang:1.24-alpine AS builder
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN go build -o ez-api ./cmd/server
+
+FROM alpine:latest
+
+WORKDIR /app
+
+COPY --from=builder /app/ez-api .
+
+EXPOSE 8080
+
+CMD ["./ez-api"]