feat: add pre-built ESP-IDF toolchain image workflow

.github/workflows/build-espidf-toolchain.yml

@@ -0,0 +1,42 @@
+name: Build ESP-IDF Toolchain Image
+
+# Only runs manually or when ESP-IDF version changes (rare)
+on:
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository_owner }}/velxio-espidf-toolchain
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build-toolchain:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push ESP-IDF toolchain image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: Dockerfile.espidf-toolchain
+          push: true
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:idf-4.4.7
+          cache-from: type=gha,scope=espidf
+          cache-to: type=gha,scope=espidf,mode=max

Dockerfile.espidf-toolchain

@@ -0,0 +1,28 @@
+# ESP-IDF toolchain image — built once, pulled many times.
+# Published to GHCR by build-espidf-toolchain.yml Action.
+# Usage: docker build -f Dockerfile.espidf-toolchain -t velxio-espidf-toolchain .
+FROM ubuntu:22.04
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    git wget flex bison gperf python3 python3-pip python3-venv \
+    cmake ninja-build ccache libffi-dev libssl-dev \
+    libusb-1.0-0 ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install ESP-IDF 4.4.7 (matches Arduino ESP32 core 2.0.17 / lcgamboa QEMU ROM)
+RUN git clone -b v4.4.7 --recursive --depth=1 --shallow-submodules \
+    https://github.com/espressif/esp-idf.git /opt/esp-idf
+
+WORKDIR /opt/esp-idf
+
+# Install toolchains for esp32 (Xtensa) and esp32c3 (RISC-V) only
+RUN ./install.sh esp32,esp32c3
+
+# Clean up large unnecessary files to reduce image size
+RUN rm -rf .git docs examples \
+    && find /root/.espressif -name '*.tar.*' -delete 2>/dev/null || true
+
+# Install Arduino-as-component for full Arduino API support in ESP-IDF builds
+RUN git clone --branch 2.0.17 --depth=1 --recursive --shallow-submodules \
+    https://github.com/espressif/arduino-esp32.git /opt/arduino-esp32 \
+ && rm -rf /opt/arduino-esp32/.git

Dockerfile.standalone

@@ -136,9 +136,9 @@ COPY deploy/nginx.conf /etc/nginx/conf.d/default.conf
 # Copy built frontend assets from builder stage
 COPY --from=frontend-builder /app/frontend/dist /usr/share/nginx/html
 
-# Copy and configure entrypoint script
+# Copy and configure entrypoint script (fix Windows CRLF → LF)
 COPY deploy/entrypoint.sh /app/entrypoint.sh
-RUN chmod +x /app/entrypoint.sh
+RUN sed -i 's/\r$//' /app/entrypoint.sh && chmod +x /app/entrypoint.sh
 
 # ── ESP32 emulation: pre-built QEMU .so + ROM binaries ──────────────────────
 # Downloaded from GitHub Release (public — no access to qemu-lcgamboa needed)