fix(pwa): drop the retired demo URL from backend CORS and og:url defaults

The public demo deployment is paused for good, so the production CLIENT_URL
fallback allowed an origin nobody can reach — a manual (non-Docker) self-host
failed every provider request with a CORS error. Default to the documented
http://localhost:4333 instead, and point og:url at the project website.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.changes/pwa-self-hosted-cors-default.md

@@ -0,0 +1,9 @@
+---
+type: fix
+area: pwa
+---
+
+Self-hosted web backends started without `CLIENT_URL` now allow the documented
+`http://localhost:4333` origin instead of the retired public demo URL, so a
+manual (non-Docker) deployment no longer fails every provider request with a
+CORS error.

apps/web-backend/src/app/web-backend-app.ts

@@ -575,10 +575,13 @@ function getClientOrigins(): string[] {
         return configured;
     }
 
+    // Production default matches the documented self-hosted setup
+    // (docker/docker-compose.yml maps the PWA to port 4333). The Docker image
+    // sets CLIENT_URL explicitly; this fallback only covers manual runs.
     return process.env['NODE_ENV'] === 'development' ||
         process.env['NODE_ENV'] === 'dev'
         ? ['http://localhost:4200']
-        : ['https://iptvnator.vercel.app'];
+        : ['http://localhost:4333'];
 }
 
 function getQueryString(req: Request, key: string): string | undefined {

apps/web/src/index.html

@@ -12,7 +12,7 @@
         />
         <meta property="og:type" content="website" />
         <meta property="og:title" content="IPTVnator" />
-        <meta property="og:url" content="https://iptvnator.vercel.app" />
+        <meta property="og:url" content="https://4gray.github.io/iptvnator/" />
         <meta
             property="og:image"
             content="https://raw.githubusercontent.com/4gray/iptvnator/electron/iptv-dark-theme.png"