feat: intégration plugin Kirby SEO

- Ajout de tobimori/kirby-seo via Composer
- snippet('seo/head') dans header.php (remplace les meta manuels)
- snippet('seo/schemas') dans footer.php pour JSON-LD
- Onglet SEO ajouté dans site.yml et tous les blueprints de pages
- Configuration SEO dans config.php (sitemap, robots, canonicalBase TODO)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

site/plugins/kirby-seo/docs/2_customization/07_gsc-setup.md

@@ -0,0 +1,45 @@
+---
+title: Setting up Google Search Console
+intro: Connect Search Console with your own Google OAuth credentials
+---
+
+By default, the Search Console integration uses a proxy to keep setup simple. If you'd rather connect directly, you can set up your own Google OAuth credentials instead. This requires a Google Cloud project with the Search Console API enabled. The API is free to use.
+
+## Create OAuth credentials
+
+Go to the [Google Cloud Console](https://console.cloud.google.com/) and create a new project, or use an existing one.
+
+Navigate to **APIs & Services** → **Credentials** → **Create Credentials** → **OAuth client ID** and configure it:
+
+- **Application type:** Web application
+- **Name:** e.g. "Kirby SEO on example.com"
+- **Authorized redirect URIs:** your site URL followed by `/__seo/gsc/callback`, e.g. `https://example.com/__seo/gsc/callback`
+
+Download the JSON file when prompted. You'll need it in the next step.
+
+Then go to **APIs & Services** → **Library**, search for "Google Search Console API" and enable it. Without this, the OAuth flow will succeed but the API requests will fail.
+
+## Add credentials to your config
+
+Place the downloaded JSON file in your `site/config` directory (e.g. `site/config/gsc-credentials.json`), then reference it in your config:
+
+```php
+<?php
+// site/config/config.php
+
+use Kirby\Data\Json;
+
+return [
+  'tobimori.seo' => [
+    'searchConsole' => [
+      'credentials' => Json::read(__DIR__ . '/gsc-credentials.json'),
+    ],
+  ],
+];
+```
+
+## Connect in the Panel
+
+Open the Panel and navigate to any page with the SEO tab. The Google Search Console section now shows a **Connect** button. Click it and authorize with your Google account. Make sure the Google account you use has access to the Search Console property for your site.
+
+After authorizing, select which Search Console property to use. The section starts showing data once the property is selected.