fix: Address code review feedback from Gemini

- Use BUILD_FROM and BUILD_ARCH for multi-architecture support
  * Replace hardcoded amd64 with BUILD_FROM in FROM statement
  * Use BUILD_ARCH variable in COPY --from directives
  * Enables building for both amd64 and aarch64 architectures

- Remove error suppression in run script for better debugging
  * Change 'cd /app || true' to 'cd /app' (fail fast on errors)
  * Remove '2> /dev/null' redirection from agent startup
  * Allow error messages to reach container logs for troubleshooting

These changes ensure the fix works correctly across all supported architectures
and provides visibility into any runtime issues.

portainer_agent/Dockerfile

@@ -2,7 +2,9 @@
 # Fix for: FATAL: PROTECTION MODE IS ENABLED! error when protection mode is OFF
 # Approach: Level 1 (standard bashio) + Level 2 (socket fallback)
 
-FROM ghcr.io/hassio-addons/base/amd64:11.1.0
+ARG BUILD_FROM
+ARG BUILD_ARCH
+FROM $BUILD_FROM
 
 # Step 1: Replace bashio v0.17.5 with main branch for improved API error handling
 RUN rm -rf /usr/lib/bashio /usr/bin/bashio && \
@@ -15,7 +17,7 @@ RUN rm -rf /usr/lib/bashio /usr/bin/bashio && \
     rm -rf /tmp/bashio /tmp/bashio.tar.gz
 
 # Step 2: Get agent from official image
-COPY --from=ghcr.io/alexbelgium/portainer_agent-amd64:alpine-sts /app /app
+COPY --from=ghcr.io/alexbelgium/portainer_agent-${BUILD_ARCH}:alpine-sts /app /app
 
 # Step 3: Add tzdata and timezone support
 RUN apk add --no-cache tzdata
@@ -28,7 +30,7 @@ ENV S6_CMD_WAIT_FOR_SERVICES=1 \
     S6_SERVICES_GRACETIME=0
 
 # Step 5: Copy rootfs from official image
-COPY --from=ghcr.io/alexbelgium/portainer_agent-amd64:alpine-sts / /
+COPY --from=ghcr.io/alexbelgium/portainer_agent-${BUILD_ARCH}:alpine-sts / /
 
 # Step 6: Override the run script with simplified protection mode check
 RUN mkdir -p /etc/services.d/portainer_agent
@@ -94,9 +96,9 @@ bashio::require.unprotected.fixed
 bashio::log.info "Starting Portainer Agent"
 
 # Launch app
-cd /app || true
+cd /app
 if bashio::config.has_value 'PORTAINER_AGENT_ARGS'; then
-    ./agent "$PORTAINER_AGENT_ARGS" 2> /dev/null
+    ./agent "$PORTAINER_AGENT_ARGS"
 else
     ./agent
 fi