chore: bump to v0.9.19-rc.1 and add local OpenAPI build support

- Add release candidate (rc) support to release.sh with latestRC tagging
- Bump VERSION, backend pyproject.toml, and frontend package.json to 0.9.19-rc.1
- Add local frontend/openapi.json so build no longer needs running backend
- Update generate:types and validate-types.sh to use local openapi.json
- Fix frontend tests: remove unused imports/variables and update mock data

frontend/scripts/validate-types.sh

@@ -17,17 +17,23 @@ GENERATED_FILE="${TYPES_DIR}/generated.ts"
 TEMP_FILE=$(mktemp)
 trap "rm -f $TEMP_FILE" EXIT
 
-# Check if backend is accessible
+# Determine OpenAPI source: local file or backend URL
 BACKEND_URL="${BANGUI_BACKEND_URL:-http://localhost:8000}"
-if ! curl -sf "${BACKEND_URL}/api/openapi.json" > /dev/null 2>&1; then
-  echo "❌ Backend not accessible at ${BACKEND_URL}/api/openapi.json" >&2
+OPENAPI_SOURCE=""
+
+if [[ -f "${FRONTEND_DIR}/openapi.json" ]]; then
+  OPENAPI_SOURCE="${FRONTEND_DIR}/openapi.json"
+  echo "📋 Validating OpenAPI schema types (local openapi.json)..."
+elif curl -sf "${BACKEND_URL}/api/openapi.json" > /dev/null 2>&1; then
+  OPENAPI_SOURCE="${BACKEND_URL}/api/openapi.json"
+  echo "📋 Validating OpenAPI schema types (backend ${BACKEND_URL})..."
+else
+  echo "❌ Backend not accessible at ${BACKEND_URL}/api/openapi.json and no local openapi.json found" >&2
   exit 2
 fi
 
-echo "📋 Validating OpenAPI schema types..."
-
 # Generate types to a temporary file
-if ! npx openapi-typescript "${BACKEND_URL}/api/openapi.json" -o "$TEMP_FILE" 2>&1; then
+if ! npx openapi-typescript "${OPENAPI_SOURCE}" -o "$TEMP_FILE" 2>&1; then
   echo "❌ Failed to generate types from OpenAPI schema" >&2
   exit 3
 fi