Make blacklist override whitelist

Change filter evaluation so blacklist matches take precedence over whitelist matches. Updated evaluator logic to skip entries when blacklist and whitelist both match, adjusted related branches to reflect the new decision flow, and updated a feeds.py comment to clarify the combined decision. Also updated blacklist/whitelist templates copy to reflect the new precedence and adjusted tests to expect blacklist-wins behavior.

discord_rss_bot/templates/blacklist.html

@@ -22,7 +22,7 @@
                             <p class="mb-2">
                                 Plain text matching is case-insensitive and partial, so <code>orld</code> matches <code>World of Warcraft</code>.
                             </p>
-                            <p class="mb-2">Whitelist matches still win. If an entry matches both, the preview keeps it as sent.</p>
+                            <p class="mb-2">Blacklist matches win. If an entry matches both, the preview keeps it as skipped.</p>
                             <p class="mb-0">Keep the left side for editing and the right side for checking what gets removed.</p>
                         </div>
                     </div>

discord_rss_bot/templates/whitelist.html

@@ -20,7 +20,7 @@
                             <p class="mb-2">
                                 Plain text matching is case-insensitive and partial, so <code>orld</code> matches <code>World of Warcraft</code>.
                             </p>
-                            <p class="mb-2">When an entry matches both lists, whitelist still wins and the preview shows it as sent.</p>
+                            <p class="mb-2">When an entry matches both lists, blacklist wins and the preview shows it as skipped.</p>
                             <p class="mb-0">Saved blacklist rules remain active while you preview whitelist edits.</p>
                         </div>
                     </div>