fix: multiple issues

1. Script warning in layout.tsx
   - Use Next.js Script component instead of plain <script>

2. QUOTA_EXCEEDED bug for chart suggestions
   - Add 'suggest_charts' to VALID_FEATURES
   - Add 'suggest_charts' to TIER_LIMITS for all tiers
   - Fix route to use 'suggest_charts' instead of invalid 'ai' feature

This fixes the issue where users with valid credit were getting
QUOTA_EXCEEDED errors because 'ai' was not a valid feature name.

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

memento-note/lib/quota-utils.ts

@@ -7,6 +7,7 @@ export const VALID_FEATURES = [
   'brainstorm_create',
   'brainstorm_expand',
   'brainstorm_enrich',
+  'suggest_charts',
 ] as const;
 
 export type FeatureName = (typeof VALID_FEATURES)[number];