docs: fix punycode example and regex delimiter in plan/spec

- xn--80aafmakjldfe1b5h.xn--p1ai decodes to "алквзелчкоеиа.рф", not
  "вашаняня.рф". Correct Punycode for "вашаняня.рф" is
  xn--80aae0ca7d8bb.xn--p1ai. Updated plan Task 2 test and spec §9.
- DomainFormatter strip-path regex '#[/?#].*$#' had the '#' delimiter
  colliding with the literal '#' inside the character class. Switched
  to tilde delimiters: '~[/?#].*$~'.

Both caught by TDD RED/GREEN loop on Task 3.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/superpowers/plans/2026-04-17-cf7-spam-to-telegram.md

@@ -207,7 +207,7 @@ final class DomainFormatterTest extends TestCase
     {
         self::assertSame(
             'вашаняня.рф',
-            DomainFormatter::humanize('xn--80aafmakjldfe1b5h.xn--p1ai')
+            DomainFormatter::humanize('xn--80aae0ca7d8bb.xn--p1ai')
         );
     }
 
@@ -284,7 +284,7 @@ final class DomainFormatter
             $host = $parsed['host'] ?? $host;
         }
         // Strip any remaining path/query
-        $host = preg_replace('#[/?#].*$#', '', $host) ?? $host;
+        $host = preg_replace('~[/?#].*$~', '', $host) ?? $host;
         // Strip leading www.
         $host = preg_replace('/^www\./i', '', $host) ?? $host;