[zeronsh]

In long conversations the rail had become a dense comb of one tick per prompt. Now it draws at most 10 ticks, and resting the pointer on it replaces it with a list of every prompt, the pattern shadcn recommends from ChatGPT web. Each entry shows the prompt and the opening of its reply.

Rail

• Up to 10 prompts, one tick each, as before. Past 10, each tick stands for an even slice of the conversation, lit while any of its prompts is on screen.
• The rail now centres between the titlebar and the composer, the same band the list opens in.
• Lighting fix: while the transcript is pinned to the bottom, the list reported no row positions, so only the prompt being read lit up. Rows are now placed from the content's end in that state, so every prompt on screen lights its tick and its list entry.

Prompt list (on hover)

• Opening: it opens after the pointer rests on the rail for 150ms, so passing over it on the way to the sidebar doesn't flash it open. It closes when the pointer leaves.
• Content: each prompt on one line, with its reply's opening on up to three. Replies are reduced to prose (no **, backticks or link targets).
• Size and position: it opens where the rail is, replacing it. It's at most three quarters of the band's height, and sizes to the gutter left of the reading column (260 to 320px) to overlap the transcript as little as possible.
• Navigation: clicking an entry glides the transcript to that prompt and the list stays open. Prompts on screen are highlighted. It opens on the prompt being read.
• Virtualized once it can't fit, so very long chats only lay out the rows in view. A short conversation's list hugs its content. Only rows whose text changed, such as a streaming reply, get re-measured.

These screenshots are from the real app, with a 24-prompt conversation pinned to the bottom. The rail, with every on-screen prompt lit:

Resting on it:

After clicking How do I tell the bakery the oven grant was denied?: the transcript jumped and the list stayed open:

A three-prompt conversation, where the list fits its content:

Notes

• The old one-tick-per-prompt rail with fisheye hover and a single-preview card is gone. The list gives every prompt a target.
• I also checked a real pointer passing quickly across the rail: the list stays closed.
• Not included: a search field and arrow-key navigation in the list.

Tests: rail:: and transcript:: UI tests (145) pass. New tests cover the 10-tick slicing (gapless, covers every prompt), the gutter-fitted width, stripping Markdown from reply previews, and the list re-measuring only rows that change as replies stream, prompts arrive or the conversation is rewound. Clippy is clean.

🤖 Generated with Claude Code

---

^{Need help on this PR? Tag @codesmith-bot with what you need.}