fix: Improve condo ID handling and add error message

Prevents client-side generation of condo IDs, delegating this to the backend/service for consistency.
Introduces an alert for save condo errors and ensures the active condo is correctly updated or set.
Adds logic to auto-select the first condo if none is active.

server/Dockerfile

@@ -1,8 +0,0 @@
-FROM node:20-alpine
-WORKDIR /app
-COPY package*.json ./
-RUN npm install
-COPY . .
-EXPOSE 3001
-CMD ["npm", "start"]
-