Add ntfy push notifications with action buttons for meal reminders

- ntfy.py: send_meal_reminder() with Home/Out HTTP action buttons, test helper
- models.py: new columns ntfy_url, ntfy_token, callback_token on users table
- meals.py: /api/ntfy-callback (public, token-authenticated), /ntfy-settings, /ntfy-test
- app.py: flask send-reminders CLI command (cron-schedulable)
- Dashboard: ntfy config form in Account Settings
- i18n: translations for all ntfy strings (en/fr/de)
- Dockerfile: include ntfy.py in COPY
- tests: 15 new tests covering callback, settings, and auth
- docs: updated AGENTS.md and doc/index.md

doc/index.md

@@ -32,6 +32,8 @@ A lightweight Flask web application for tracking household meal attendance. Memb
 ├── auth.py                 # Authentication blueprint (login, register, logout)
 ├── meals.py                # Meals blueprint (dashboard, responses, history, admin)
 ├── models.py               # Database models and helpers
+├── i18n.py                 # Internationalization (en/fr/de)
+├── ntfy.py                 # Ntfy notification helpers
 ├── requirements.txt        # Python dependencies
 ├── Dockerfile              # Container image definition
 ├── docker-compose.yml      # Container orchestration
@@ -118,6 +120,19 @@ source .env
 
 ## API / Routes
 
+### Ntfy Callback (public)
+
+| Method | Path | Description |
+|--------|------|-------------|
+| POST | `/api/ntfy-callback` | Receive ntfy action callbacks. Auth via per-user `callback_token`. Body: `{"token":"...", "meal_type":"lunch|dinner", "date":"YYYY-MM-DD", "status":"yes|no"}`. Returns 200 on success, 403 for bad token, 400 for invalid/past data. |
+
+### Ntfy Settings (authenticated)
+
+| Method | Path | Description |
+|--------|------|-------------|
+| POST | `/ntfy-settings` | Save ntfy topic URL and access token |
+| POST | `/ntfy-test` | Send a test notification to verify configuration |
+
 ### Authentication
 
 | Method | Path         | Description               |
@@ -189,3 +204,41 @@ pytest tests/ -v
 ```
 
 Tests use a temporary in-memory SQLite database (configured per test via `conftest.py`).
+
+## Ntfy Notifications
+
+Users can configure [ntfy](https://ntfy.sh) to receive push notifications with action buttons, allowing them to respond to meals directly from their phone without opening the web UI.
+
+### Setup
+
+1. Install the ntfy app on your phone and subscribe to a topic (e.g. `your-name-meals`)
+2. (Optional) Create an access token for authenticated publishing
+3. In the web UI, open **Account Settings** and enter:
+   - **Ntfy Topic URL**: Your topic (e.g. `https://ntfy.sh/your-name-meals`)
+   - **Access Token**: Your ntfy access token (if using auth)
+4. Click **Send Test** to verify it works
+
+### How It Works
+
+- Reminders are sent via the CLI command: `flask send-reminders`
+- The notification contains **Home** and **Out** buttons
+- Pressing a button sends an HTTP callback to the app, recording your response instantly
+- Tapping the notification itself opens the dashboard
+
+### Scheduling Reminders
+
+Add a cron job on the server to send reminders automatically:
+
+```bash
+# Lunch reminder at 9:00 AM
+0 9 * * * cd /path/to/app && docker compose exec meal-tracker flask send-reminders --meal lunch --base-url https://meals.ct.cozytren.ch
+
+# Dinner reminder at 5:00 PM
+0 17 * * * cd /path/to/app && docker compose exec meal-tracker flask send-reminders --meal dinner --base-url https://meals.ct.cozytren.ch
+```
+
+Or run manually:
+
+```bash
+docker compose exec meal-tracker flask send-reminders --date 2026-08-01 --meal both
+```