feat(ops): add Makefile, Dockerfile, and K8s manifests

Dockerfile

@@ -0,0 +1,29 @@
+# --- Frontend Build ---
+FROM node:20-alpine as frontend-builder
+WORKDIR /app/frontend
+COPY frontend/package*.json ./
+RUN npm install --force
+COPY frontend/ ./
+RUN npm run build
+
+# --- Backend Build ---
+FROM rust:1.77-slim as backend-builder
+WORKDIR /app/backend
+# Pre-build dependencies for caching
+COPY backend/Cargo.toml backend/Cargo.lock ./
+RUN mkdir src && echo "fn main() {}" > src/main.rs && cargo build --release && rm -rf src
+COPY backend/src ./src
+COPY backend/migrations ./migrations
+RUN cargo build --release
+
+# --- Final Image ---
+FROM debian:bookworm-slim
+RUN apt-get update && apt-get install -y sqlite3 ca-certificates && rm -rf /var/lib/apt/lists/*
+WORKDIR /app
+COPY --from=backend-builder /app/backend/target/release/attendance ./server
+COPY --from=frontend-builder /app/frontend/build ./frontend/build
+
+ENV STATIC_DIR=/app/frontend/build
+ENV DATABASE_URL=sqlite:/data/attendance.db
+EXPOSE 3000
+CMD ["./server"]