Feature Request: Functional heading indicators & persistent bookmarks on the scrollbar track

[Droyk]

Since this extension already customizes the scrollbar visually, I feel like it should improve the functional quality of the extension if add functional markers to it. something no pure styling extension currently does.

1. Heading indicators
   Show heading positions (h1, h2, h3 etc.) as small markers directly on the scrollbar track. Clicking a marker jumps to that heading. Same concept as YouTube's chapter markers on the video progress bar applied to page scroll.
   This should work on modern sites that standard scroll extensions struggle with AI chat interfaces (Claude, ChatGPT, Gemini), Spotify, Reddit, X. On those sites, user messages and AI responses, album names, posts etc. should appear as heading markers on the track.
   Rather than scanning and showing all headings at once, markers should appear progressively. only for content already rendered and scrolled past, plus what's currently visible:
   Optional controls worth considering:

   • Toggle indicators on/off
   • Choose which heading levels to show (h1 only vs h1–h3)
   • Hover on a marker shows the heading text

2. Persistent Manual bookmarks on the scrollbar
   Beyond headings, it would be great to also place persistent manual bookmarks directly on the scrollbar track. clicking a bookmark marker jumps straight to that position, no list or menu needed. Persistence across refreshes and future visits is the most critical part of this. Persistence is what makes them actual bookmarks. So on sites like Spotify a user can pin specific album positions in a long list and then can jump directly back on any manual bookmark (exact or approx location) on every subsequent visit.

   For the bookmark experience to be truly seamless, 3 things are needed:

   1. Keyboard-first creation i.e. when saving a bookmark via keyboard, auto-name it using the page/tab title + an incrementing number coz manual naming breaks flow; auto-naming keeps hands off the mouse entirely. So 3 specific keyboard hotkeys would needed to be added
      - One that shows an overview of all active bookmarks and their assigned keys
      - One that cycles through bookmarks in reverse-chronological order (most recent → oldest)
      - One that jumps directly to a specific bookmark by its assigned key that one can see by the overview
   2. Marker management without opening the extension i.e. right-clicking a marker directly on the scrollbar should allow renaming or deleting it, without opening any separate menu or list. Creation is keyboard-first; management should be equally frictionless.
   3. Position anchoring i.e. on generative sites, headings shift position as new content is added below. A bookmark saved at 40% scroll may no longer be near the same content after more messages load. The extension should save by nearest heading anchor rather than raw scroll percentage though with an option to choose between the two.

The heading indicators alone would already be a significant improvement. The bookmark layer builds naturally on top of it. Happy to elaborate on any part of this.