Improve Twitter/X link handling and text formatting

- Use FxTwitter API for full note tweet text (with syndication API fallback)
- Save Twitter posts based on media content:
  - Videos → embed type (proxied video)
  - Images → image type (gallery)
  - Text-only → quote type
- Add granular preview badges: 'X VIDEO', 'X GALLERY', 'X POST'
- Preserve formatting/spacing with white-space: pre-wrap for quotes and descriptions
- Rename VideoInfo to EmbedInfo for better semantic clarity

internal/static/css/app.css

@@ -194,6 +194,7 @@ button, input, textarea, select {
 	font-style: italic;
 	line-height: 1.6;
 	margin-bottom: 0.75rem;
+	white-space: pre-wrap;
 }
 
 .quote-card blockquote::before {
@@ -376,6 +377,7 @@ button, input, textarea, select {
 	font-style: italic;
 	line-height: 1.6;
 	margin-bottom: 1rem;
+	white-space: pre-wrap;
 }
 
 .quote-detail blockquote::before {
@@ -405,6 +407,7 @@ button, input, textarea, select {
 .item-meta .description {
 	margin-bottom: 1rem;
 	color: var(--gray-3);
+	white-space: pre-wrap;
 }
 
 .item-meta .source-link {
@@ -597,6 +600,7 @@ input[type="file"] {
 .preview-description {
 	font-size: 0.85rem;
 	color: var(--gray-3);
+	white-space: pre-wrap;
 }
 
 /* Image Gallery (detail page) */