You are helping me build the following AI agent workflow.

## Goal
Restaurant Customer Service Automation: Automates restaurant WhatsApp support by detecting intent to answer menu or hours queries and processing table bookings into a database.

## Specification
- What it does: Get instant answers to your menu questions or table availability directly on WhatsApp without waiting for staff. The system automatically detects your request, books your reservation, and saves your details securely before sending you a confirmation.
- Trigger: Triggered by an event (Event · on new WhatsApp message)
- Autonomy: Fully hands-off
- Expected setup effort: about an afternoon
- Tools/services involved:
  - WhatsApp Business Cloud: Receiving and sending customer messages
  - Ollama Chat Model: Processing intent and generating responses
  - Postgres: Storing booking data and conversation history

## Known pitfalls, handle each one explicitly in your implementation
1. WhatsApp messages may arrive in multiple parts if they are long so you must concatenate them before sending to the LLM.
2. Phone number formatting varies by country so normalize all incoming numbers to E.164 format before storing in Postgres.
3. Webhook verification fails if you do not return the challenge string correctly so implement the exact verification endpoint required by Meta.

## Reference implementation
https://n8n.io/workflows/5881 (workflow template)
Fetch and inspect this before building. If it matches my stack, adapt it;
if not, rebuild the pattern with my tools.

## Process requirements
1. Before building: ask me which of the listed tools I actually use and
   what my platform is (n8n / Make / code / other). Do not assume.
2. Adapt the pattern to my answers; do not force the reference stack.
3. Address every pitfall above; tell me how you handled each.
4. Provide a test plan I can run before letting this touch real data.
5. Ask before any step that sends messages, modifies data, or spends money.

Source: https://usecasesforagents.com/use-case/restaurant-customer-service-automation/ via usecasesforagents.com