chore: add Docker image

Author: ayobi

.dockerignore

@@ -0,0 +1,17 @@
+cat > .dockerignore <<'EOF'
+# Ignore everything at repo root
+*
+
+# Keep docker config
+!Dockerfile
+!.dockerignore
+
+# Keep Rust build inputs
+!Cargo.toml
+!Cargo.lock
+!src/
+!src/**
+!build.rs
+!.cargo/
+!.cargo/**
+EOF

Dockerfile

@@ -0,0 +1,21 @@
+# -------- builder --------
+FROM rust:1-bookworm AS builder
+
+WORKDIR /app
+
+COPY Cargo.toml Cargo.lock ./
+COPY src ./src
+
+RUN cargo build --release --locked
+
+# -------- runtime --------
+FROM debian:bookworm-slim AS runtime
+
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends hmmer ca-certificates \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /app/target/release/itsxrust /usr/local/bin/itsxrust
+
+ENTRYPOINT ["itsxrust"]
+CMD ["--help"]