Delimit the subreddit filter with ~ so it actually runs

The pattern used # as its delimiter and excluded a literal # inside the character class, so PCRE
ended the pattern early and the match never fired. It read as the filter doing nothing. The unit
test missed it by asserting against a retyped copy of the regex rather than the one in the file,
which is the only version that matters.

Plugin/unraid/include/ai_web.php

@@ -188,7 +188,10 @@ function vv_ai_web_degoog(string $q): ?array {
     $rows = [];
     foreach ($d['results'] ?? [] as $r) {
         $url = (string)($r['url'] ?? '');
-        if (preg_match('#^https?://(?:[a-z0-9-]+\.)*reddit\.com/r/[^/?#]+/?$#i', $url)) continue;
+        // Delimited with ~, not #. The character class has to exclude a literal # (a fragment),
+        // and with # as the delimiter PCRE ends the pattern there and the match silently never
+        // fires — which is exactly what happened, and it looked like the filter doing nothing.
+        if (preg_match('~^https?://(?:[a-z0-9-]+\.)*reddit\.com/r/[^/?#]+/?$~i', $url)) continue;
         $rows[] = ['title'   => $r['title'] ?? '',
                    'url'     => $url,
                    'snippet' => ($r['snippet'] ?? '') !== '' ? $r['snippet'] : ($r['content'] ?? '')];