fix: add git and packaging to runtime image for ESP-IDF cmake

- git is required by ESP-IDF cmake to resolve submodules and version info
- packaging Python package is required by ESP-IDF Python dependency checks
  during cmake configure step

Without these, ESP32 compilation fails at cmake configure with:
  "Some Python dependencies must be installed"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile.standalone

@@ -96,8 +96,10 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     cmake \
     ninja-build \
     libusb-1.0-0 \
+    git \
     && apt-get clean \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+    && pip install --no-cache-dir packaging
 
 # Install arduino-cli into /usr/local/bin directly (avoids touching /bin)
 RUN curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh \