Add advanced canvas editing and Ubuntu deployment

backend/docker-entrypoint.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Seed design templates into the mounted volume on first boot.
+SEED_DIR="/app/service_design_templates_seed"
+TARGET_DIR="/app/service_design_templates"
+if [[ -d "$SEED_DIR" ]]; then
+  mkdir -p "$TARGET_DIR"
+  # only copy when target has no template.json yet
+  if ! find "$TARGET_DIR" -type f -name 'template.json' 2>/dev/null | grep -q .; then
+    echo "[entrypoint] seeding design templates into volume..."
+    cp -a "$SEED_DIR"/. "$TARGET_DIR"/
+  fi
+fi
+
+# Ensure runtime dirs exist
+mkdir -p \
+  /app/service_workspace \
+  /app/service_assets \
+  /app/service_projects \
+  /app/service_fonts \
+  /app/service_design_templates
+
+exec "$@"