Increase minimum check interval to 60 seconds

PokemonCenter's Imperva bot protection bans IPs that hit
too frequently. 10 seconds was too aggressive.

- New minimum: 60 seconds
- New default: 90 seconds
- Updated popup UI to reflect safer limits

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

chrome-extension/background.js

@@ -2,7 +2,7 @@
 
 const DEFAULT_CONFIG = {
   discordWebhook: "",
-  checkIntervalSeconds: 15, // Now in SECONDS, not minutes!
+  checkIntervalSeconds: 90, // Minimum 60 to avoid PokemonCenter bot detection
   enabled: true,
   urls: [
     "https://www.pokemoncenter.com/category/tcg-cards?sort=relevance"
@@ -55,7 +55,7 @@ function scheduleNextCheck() {
     return;
   }
 
-  const intervalMs = Math.max(10, config.checkIntervalSeconds) * 1000; // Min 10 seconds
+  const intervalMs = Math.max(60, config.checkIntervalSeconds) * 1000; // Min 60 seconds to avoid bot detection
 
   setTimeout(async () => {
     if (!isChecking && config.enabled) {