Extension Bookmarks tab: see your saved posts for the profile you're on

A new Bookmarks tab in the extension sidebar. The extension already recognizes the profile you're browsing (name + fbUserId). When you open the tab on someone's profile, it shows every post of that person you've bookmarked, pulled from your account.

Deliberately minimal so there are no thumbnail-loading problems:

• No images. Rows only.

• Each row: first line of the post text, the date, the media type (video, photo, text, link).

• Clicking a row opens the original post in a new tab via its URL.

• Not on a recognizable profile? Show all bookmarks, or an empty state that says to browse a profile to see saved posts for that person. UX decides which.

Why this is its own feature

This is the recall side of bookmarking, and it works no matter where a bookmark came from (dashboard or anywhere else). You land on a creator's profile and instantly see everything of theirs you've ever saved, without leaving Facebook. It turns the extension from a capture tool into something you check every time you visit a profile.

Build notes

• Profile recognition already exists in the capture flow; this reuses fbUserId matching.

• The tab reads from the user's saved posts in their account; it does not capture anything new.

• Keep the row rendering dumb and fast: text, date, type badge, link. Nothing that fetches media.

Acceptance criteria

1. Bookmarks tab appears in the extension sidebar.

2. On a recognized profile, the tab lists only that person's saved posts, newest first.

3. Rows show text snippet, date, and media type; no images load.

4. Clicking a row opens the original post in a new tab.

5. Unrecognized context shows the agreed fallback (all bookmarks or empty state) instead of an error.