feat: install Cursor Agent CLI in image with API key auth

Bake agent into the pi user PATH; pass CURSOR_API_KEY from .env so no browser login is required.

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -41,9 +41,15 @@ ENV HOME=/home/pi \
   PI_WEB_HOST=0.0.0.0 \
   PI_WEB_PORT=8504 \
   PI_WEB_ALLOWED_HOSTS=pi.schwenk.online \
-  PATH="/usr/local/bin:${PATH}"
+  PATH="/home/pi/.local/bin:/home/pi/.cursor/bin:/usr/local/bin:${PATH}"
 
 USER pi
+
+# Cursor Agent CLI — auth via CURSOR_API_KEY at runtime (not baked into image)
+# https://cursor.com/docs/cli/installation
+RUN curl -fsSL https://cursor.com/install | bash \
+  && agent --version
+
 WORKDIR /workspaces
 
 EXPOSE 8504