feat: add Docker support with Dockerfile and docker-compose, update API URLs to use base_url

backend/Dockerfile

@@ -0,0 +1,40 @@
+# ── Stage 1: builder ──────────────────────────────────────────────────────────
+FROM rust:1.88-slim-bookworm AS builder
+
+# Build dependencies for native libs (OpenSSL via rustls not needed, but sqlx needs pkg-config)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    pkg-config \
+    libssl-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Cache dependency compilation separately from source
+COPY Cargo.toml Cargo.lock ./
+
+# Create a dummy main so Cargo can compile deps without our source
+RUN mkdir src && echo "fn main() {}" > src/main.rs
+RUN cargo build --release --bin meowspool 2>/dev/null; true
+
+# Now copy real source and migrations
+COPY src ./src
+COPY migrations ./migrations
+
+# Touch main.rs so Cargo knows it changed, then build for real
+RUN touch src/main.rs && cargo build --release --bin meowspool
+
+# ── Stage 2: runtime ──────────────────────────────────────────────────────────
+FROM debian:bookworm-slim AS runtime
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=builder /app/target/release/meowspool ./meowspool
+COPY --from=builder /app/migrations ./migrations
+
+EXPOSE 8080
+
+CMD ["./meowspool"]