BlueskyPostCard.svelte: 1. Added renderRichText for links, mentions, and hashtags using post facets. 2. Refactored post layout into recursive postContent snippet for nested/quoted posts. 3. Added support for videos, external link cards, and improved author display. atproto.ts: 1. Added helpers for blob URL building and CID extraction. 2. Implemented robust extractImageUrlsFromValue for images/videos in various embed structures. 3. Extended BlueskyPost model with author, facets, video, externalLink, etc. 4. Introduced recursive fetchPostFromUri to fetch quoted posts (up to 2 levels deep). 5. Improved caching and fallback handling for post fetching.