build: bump MSRV to 1.88, update Dockerfile and CI

rmcp-macros 1.5.0 (transitive dep via rmcp 1.4.0) requires darling 0.23.0
which sets rust-version = "1.88". Update all MSRV references accordingly.

Author: bug-ops

.github/workflows/ci.yml

@@ -61,7 +61,7 @@ jobs:
           - os: ubuntu-latest
             rust: beta
           - os: ubuntu-latest
-            rust: "1.85"  # MSRV
+            rust: "1.88"  # MSRV
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # actions/checkout v6
       - uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # dtolnay/rust-toolchain master

Cargo.toml

@@ -5,7 +5,7 @@ resolver = "2"
 [workspace.package]
 version = "0.3.6"
 edition = "2024"
-rust-version = "1.85"
+rust-version = "1.88"
 authors = ["Andrei G. <k05h31@gmail.com>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/bug-ops/mcpls"

Dockerfile

@@ -1,42 +1,45 @@
 # Multi-stage build for mcpls
-# Build stage uses rust:1.85-slim, runtime uses debian:bookworm-slim
+# Build stage uses rust:1.88-slim, runtime uses debian:bookworm-slim
 
 # Build stage
-FROM rust:1.85-slim as builder
+FROM rust:1.88-slim AS builder
 
 WORKDIR /app
 
-# Copy workspace files
+# Cache dependencies separately from source code.
+# Copy manifests first, build a dummy main to populate the registry cache,
+# then overwrite with real sources. This layer is invalidated only when
+# Cargo.toml or Cargo.lock changes.
 COPY Cargo.toml Cargo.lock ./
+COPY crates/mcpls-core/Cargo.toml ./crates/mcpls-core/
+COPY crates/mcpls-cli/Cargo.toml ./crates/mcpls-cli/
+RUN mkdir -p crates/mcpls-core/src crates/mcpls-cli/src && \
+    echo "pub fn main() {}" > crates/mcpls-core/src/lib.rs && \
+    echo "fn main() {}" > crates/mcpls-cli/src/main.rs && \
+    cargo build --release --package mcpls && \
+    rm -rf crates/mcpls-core/src crates/mcpls-cli/src
+
+# Now copy real sources and rebuild only the changed crates
 COPY crates/ ./crates/
-
-# Build release binary
 RUN cargo build --release --package mcpls
 
 # Runtime stage
 FROM debian:bookworm-slim
 
-# Install runtime dependencies (CA certificates for HTTPS)
 RUN apt-get update && apt-get install -y \
     ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
-# Copy only the binary from builder stage
 COPY --from=builder /app/target/release/mcpls /usr/local/bin/mcpls
 
-# Create config directory
-RUN mkdir -p /etc/mcpls
+RUN mkdir -p /etc/mcpls && \
+    useradd -m -u 1000 mcpls && \
+    chown mcpls:mcpls /etc/mcpls
 
-# Set default environment variables
 ENV MCPLS_CONFIG=/etc/mcpls/mcpls.toml
 ENV MCPLS_LOG=info
 
-# Run as non-root user for security
-RUN useradd -m -u 1000 mcpls && \
-    chown -R mcpls:mcpls /etc/mcpls
-
 USER mcpls
 WORKDIR /home/mcpls
 
 ENTRYPOINT ["mcpls"]
-CMD []