README.md update.

README.md

@@ -19,6 +19,8 @@
 A public demo instance is available here:
 
 👉 https://guide.demo.johnnybegood.fr/
+Health page: https://guide.demo.johnnybegood.fr/health.php
+Setup page (read only on demo): https://guide.demo.johnnybegood.fr/setup.php
 
 This demo runs with sample XMLTV feeds to showcase the interface.
 
@@ -45,6 +47,7 @@ This demo runs with sample XMLTV feeds to showcase the interface.
 - ⚙️ **Re-editable setup** — protected by an admin key, no SSH required to update config
 - 🩺 **Admin health page** — check config, XMLTV, M3U, response times, and metadata coverage
 - 🖨️ **24h printable export** — generate a polished daily schedule for PDF/print and PNG export
+- 🧪 **Demo mode** — drop a `.demo` file at the project root to expose admin pages safely in read-only mode
 - 🔔 **Update notifications** — a badge appears in the topbar when a new release is available on GitHub
 - 🔄 **Auto-reload** EPG every 30 minutes
 - 0️⃣ **Zero build tooling** — vanilla PHP/JS/CSS, with bundled local assets
@@ -234,6 +237,8 @@ http://guide.your-domain.com/health.php
 http://guide.your-domain.com/export.php
 ```
 
+`health.php` is admin-only by default. `export.php` is public so visitors can print or save the daily guide.
+
 ---
 
 <details>
@@ -280,6 +285,88 @@ nano /var/www/gridtv/config.json
 
 </details>
 
+<details>
+<summary>Health page</summary>
+
+## 🩺 Health page
+
+The health page gives you a quick operational view of your instance without needing SSH first:
+
+- checks whether `config.json` exists and is writable by PHP
+- shows the current PHP version and whether `php-curl` / `php-xml` are loaded
+- tests each configured XMLTV source
+- tests each configured M3U playlist when present
+- shows response times, final URL after redirects, content type, and basic metadata counts
+- highlights XMLTV coverage for things like `category`, `sub-title`, `rating`, and `date`
+
+By default, the page is protected by the same admin key as `setup.php`:
+
+```text
+http://guide.your-domain.com/health.php
+```
+
+If you enable demo mode with a `.demo` file, visitors can open the page without the key.
+
+---
+
+</details>
+
+<details>
+<summary>24h export</summary>
+
+## 🖨️ 24h export
+
+The export page builds a printable 24-hour TV guide from the current XMLTV source:
+
+- filter by source
+- choose the target date
+- restrict the export to a time window (`00h-24h`, morning, afternoon, evening, prime time)
+- limit the number of visible channels
+- choose between a readable card layout or a dense timeline
+- export to PDF via the browser print dialog
+- export to PNG directly from the page
+
+Public URL:
+
+```text
+http://guide.your-domain.com/export.php
+```
+
+This page is intentionally public so you can share a “TV guide sheet” with other people.
+
+---
+
+</details>
+
+<details>
+<summary>Demo mode</summary>
+
+## 🧪 Demo mode
+
+If you want to expose your instance publicly without letting visitors modify it, create an empty `.demo` file at the project root:
+
+```bash
+touch /var/www/gridtv/.demo
+```
+
+When `.demo` exists:
+
+- `setup.php` becomes read-only
+- `health.php` can be viewed without entering the admin key
+- visitors can inspect the current configuration safely
+
+To disable demo mode:
+
+```bash
+rm /var/www/gridtv/.demo
+```
+
+> `.demo` is ignored by Git, just like `config.json`.
+
+---
+
+</details>
+
 <details>
 <summary>Project structure</summary>
 
@@ -295,7 +382,7 @@ gridtv/
 ├── version.json         # Current version (used for update check)
 ├── Dockerfile
 ├── docker-compose.yml
-├── .gitignore           # config.json excluded
+├── .gitignore           # local instance files excluded
 ├── locales/             # i18n translation files
 │   ├── en.json
 │   ├── fr.json