[Feature]: Minimap arrows/keybindins to navigate to previous/next user prompt

[teloverge]

Before submitting

• I searched existing issues and did not find a duplicate.
• I am describing a concrete problem or use case, not just a vague idea.

Area

apps/web

Problem or use case

Rapid navigation to previous/next user prompt (OrchestrationMessage.role: === "user").

Minimap can be hard to select a specific message.

Proposed solution

Up/down "arrows" centered below minimap navigate to previous/next user prompt. Optional keybindings [Ctrl-Up/Ctrl-Down] when focused on conversation history.

MessageTimeline already tracks location [state.positionAtIndex(rowIndex)] in conversation history.

Fade out with timeline if side gutter lacks space.

Why this matters

Finding prompts quickly in long conversation history eliminates unnecessary scrolling.

Support AI developer/content creators that demonstrate "live" the prompts they used in complex projects/threads.

Smallest useful scope

Either the UI arrows or keybindings.

Alternatives considered

Create separate issue for minimap carousel with "center stage" highlighting (aka "fisheye menu") (center=200%, previous/next=150%, all others = current minimap line width). Minimap already implements "content reveal" for hovered item. The carousel would actually work best for vertically constrained windows. Concept generally based on Apple's 3D cylindrical vertical carousel (wheel).

More distinct colorization of prompts (like iMessage blue/green distinction between sender/receiver).
Allow arrows inside the side gutter.

Risks or tradeoffs

Risk:

• Compact arrows below minimap for previous/next selection is low risk. MessageTimeline already supports scrollToIndex().
• Carousel solution would require custom react component that could impact performance

Edge cases:

• No previous/next prompt available.
• Many and verbose turns between prompts requires tracing current display position to previous/next prompt.

Examples or references

Compact up/down arrows centered below minimap:

Minimap carousel would look similar to this, but with much less vertical spacing between neighbors.

Contribution

• I would be open to helping implement this.

[joshoastler]

I've filed #6152 for a related but distinct idea, cross-linking it here since anyone thinking about prompt navigation will land on this issue first.

Rather than navigating to the previous user prompt, #6152 asks for the latest user message to be pinned at the top of the chat viewport — two or three lines with the overflow fading, always on, with a setting to disable it. The difference is retrieval versus orientation: your arrows and keybindings make finding my prompt fast, but I still have to notice I have lost my bearings and then act to recover them, and as you note, the minimap "can be hard to select a specific message". A pinned line answers the question before I ask it.

The two seem complementary rather than competing — the pin covers "what am I currently asking this thread to do", the arrows cover "take me to any earlier prompt". Both are hitting the same underlying friction from opposite ends.

[juliusmarminge]

Resolved by #8531 (previous/next turn navigation on the thread minimap).