add dockerfile multi-stage build

.dockerignore

@@ -0,0 +1,6 @@
+.zig-cache/
+zig-out/
+mail/
+*.md
+.mise.toml
+.tool-versions

Dockerfile

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+# Build stage
+FROM debian:bookworm-slim AS builder
+
+# Install build dependencies
+RUN apt-get update && apt-get install -y \
+    curl \
+    xz-utils \
+    git \
+    pkg-config \
+    libnotmuch-dev \
+    libgmime-3.0-dev \
+    libglib2.0-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Zig 0.15.2
+RUN curl -fL https://ziglang.org/download/0.15.2/zig-x86_64-linux-0.15.2.tar.xz | tar -xJ -C /usr/local && \
+    ln -s /usr/local/zig-x86_64-linux-0.15.2/zig /usr/local/bin/zig
+
+# Copy source code
+WORKDIR /build
+COPY . .
+
+# Build in release mode with baseline CPU features for portability
+RUN zig build -Doptimize=ReleaseSafe -Dcpu=baseline
+
+# Runtime stage
+FROM debian:bookworm-slim
+
+# Install runtime dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    libnotmuch5 \
+    libgmime-3.0-0 \
+    libglib2.0-0 \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy binary and static files
+COPY --from=builder /build/zig-out/bin/zetviel /usr/local/bin/zetviel
+COPY --from=builder /build/static /app/static
+
+WORKDIR /app
+
+# Set environment variable for notmuch database
+ENV NOTMUCH_PATH=/mail
+
+EXPOSE 5000
+
+ENTRYPOINT ["/usr/local/bin/zetviel"]