chore(docker): add containerized development setup

backend/.dockerignore

@@ -0,0 +1,7 @@
+.env
+*.db
+*.sqlite
+*.sqlite3
+bin
+coverage.out
+*.test

backend/Dockerfile

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+FROM golang:1.27.1-alpine AS build
+
+WORKDIR /src
+
+ARG GOPROXY=https://package-mirror.liara.ir/repository/go/
+ENV GOPROXY=$GOPROXY
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY cmd ./cmd
+COPY internal ./internal
+
+RUN CGO_ENABLED=0 GOOS=linux go build \
+    -trimpath \
+    -ldflags="-s -w" \
+    -o /out/api \
+    ./cmd/api
+
+FROM alpine:3.22
+
+RUN apk add --no-cache ca-certificates \
+    && addgroup -S app \
+    && adduser -S -G app app \
+    && mkdir /data \
+    && chown app:app /data
+
+WORKDIR /app
+
+COPY --from=build /out/api ./api
+
+USER app
+
+EXPOSE 8080
+
+CMD ["./api"]