feat(docs): add sponsor page with GitHub Sponsors and PayPal options

- /sponsor landing page lists both options with feature cards
- Navbar heart icon and footer sponsor link both point to /sponsor
  instead of directly to GitHub Sponsors, so PayPal is equally reachable
- No GitHub account required for PayPal path

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

docs/content/blog/2026-05-welcome.md

@@ -27,7 +27,7 @@ If your speaker was registered with Bose before the shutdown, AfterTouch can **m
 your existing account and presets** in a single step — no reconfiguration on the
 speaker side. If you are setting up a factory-reset or brand-new speaker, AfterTouch
 handles that path too, guiding you through Wi-Fi pairing and account creation locally.
-See the [Migration Guide](/docs/guides/MIGRATION-GUIDE/) for step-by-step instructions.
+See the [Migration Guide](../docs/guides/MIGRATION-GUIDE.md) for step-by-step instructions.
 
 ### Internet radio — TuneIn and RadioBrowser
 
@@ -89,7 +89,7 @@ AfterTouch runs on any machine your speakers can reach:
    home network. AfterTouch handles TLS certificate generation and DNS configuration
    for this scenario.
 
-All three paths are documented in the [Deployment guides](/docs/guides/).
+All three paths are documented in the [Deployment Overview](../docs/guides/DEPLOYMENT-OVERVIEW.md).
 
 ## Current release
 

docs/content/sponsor.md

@@ -0,0 +1,22 @@
+---
+title: Sponsor AfterTouch
+sidebar:
+  exclude: true
+---
+
+AfterTouch is free, open source, and maintained in spare time. If it is keeping your speakers alive, a small contribution helps cover hosting, development time, and the hardware needed for testing.
+
+{{< hextra/feature-grid >}}
+  {{< hextra/feature-card
+    title="GitHub Sponsors"
+    subtitle="Recurring or one-time sponsorship via GitHub. Requires a GitHub account."
+    icon="github"
+    link="https://github.com/sponsors/gesellix"
+  >}}
+  {{< hextra/feature-card
+    title="PayPal"
+    subtitle="One-time contribution via PayPal. No GitHub account needed."
+    icon="cash"
+    link="https://paypal.me/gesellix"
+  >}}
+{{< /hextra/feature-grid >}}