- Implemented configurable public URL rewriting.

What changed:
Added pretty URL helpers/default setting in 
[includes/db.php](/Users/tyemeclifford/Documents/GH/mediaplayer/includes/db.php).
Added root rewrite rules in 
[.htaccess](/Users/tyemeclifford/Documents/GH/mediaplayer/.htaccess):/v/<slug>
/all
/search/<query>

Added Admin → Settings “Public URL Style” toggle in 
[admin/settings.php](/Users/tyemeclifford/Documents/GH/mediaplayer/admin/settings.php), 
defaulting to pretty URLs.
Updated public/player/catalogue/embed/admin preview links to use the 
configured URL style.
Added redirects from legacy ?v= and ?q= URLs to pretty routes when 
rewriting is enabled.
Documented deployment and fallback behavior in 
[README.md](/Users/tyemeclifford/Documents/GH/mediaplayer/README.md).

admin/youtube_import.php

@@ -587,7 +587,7 @@ render_head('YouTube Importer — Admin', '
       </div>
     </div>
     <nav class="topbar-social">
-      <a class="social-pill" href="../index.php" target="_blank">View Site</a>
+      <a class="social-pill" href="<?= h(public_absolute_url(public_home_url())) ?>" target="_blank">View Site</a>
       <a class="social-pill" href="logout.php">Logout</a>
     </nav>
   </header>