feat: add first page with auth and containers list and agents

agent/Dockerfile

@@ -0,0 +1,36 @@
+# Context: project root (needed so build.rs can access proto/)
+FROM rust:slim AS builder
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    protobuf-compiler \
+    pkg-config \
+    libssl-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /src
+
+# Copy proto first (referenced by build.rs as ../proto/...)
+COPY proto/ ./proto/
+
+# Cache dependencies: copy manifests, build with dummy main, then discard.
+COPY agent/Cargo.toml agent/Cargo.lock ./agent/
+COPY agent/build.rs ./agent/
+WORKDIR /src/agent
+RUN mkdir src && echo "fn main(){}" > src/main.rs && \
+    cargo build --release && \
+    rm -rf src
+
+# Full build.
+COPY agent/src ./src
+RUN touch src/main.rs && cargo build --release
+
+# ── Runtime ───────────────────────────────────────────────────────────────────
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /src/agent/target/release/containarr-agent /usr/local/bin/containarr-agent
+
+ENTRYPOINT ["containarr-agent"]