feat(docker): optimize Dockerfile for multi-stage builds

- Introduced a builder stage to separate build dependencies.
- Added a dev stage for runtime dependencies and live reload tools.
- Reduced image size by cleaning up unnecessary files in the builder
stage.
- Improved build efficiency by copying only necessary files to the dev
stage.

Dockerfile.dev

@@ -1,18 +1,34 @@
-FROM golang:1.24-alpine 
-
+# ----------- Builder Stage -----------
+FROM golang:1.24-alpine AS builder
 WORKDIR /app
 
-RUN apk update \
-  && apk add --no-cache build-base \
-  && apk add --no-cache golangci-lint \
-  && go install github.com/air-verse/air@latest \
-  && go install github.com/a-h/templ/cmd/templ@latest
+RUN apk update && apk add --no-cache build-base
 
 COPY go.mod go.sum ./
 RUN go mod download
 
 COPY . .
 
+RUN go build -ldflags="-s -w" -o rentease main.go
+
+# Install air and templ for live reload and templating in dev
+RUN go install github.com/air-verse/air@latest \
+  && go install github.com/a-h/templ/cmd/templ@latest \
+  && rm -rf /go/pkg/mod /root/.cache/go-build
+
+# ----------- Dev Stage -----------
+FROM golang:1.24-alpine AS dev
+WORKDIR /app
+
+# Install runtime dependencies
+RUN apk add --no-cache ca-certificates && apk add --no-cache golangci-lint
+
+# Copy only necessary files from builder
+COPY --from=builder /app/rentease ./rentease
+COPY --from=builder /app/assets ./assets
+COPY --from=builder /go/bin/air /go/bin/templ /go/bin/
+COPY . .
+
 EXPOSE 8000
 
-CMD [ "air", "-c", ".air.toml" ]
+CMD ["air", "-c", ".air.toml"]