Session ticks look off for generated sessions (short samples)

[coderabbitai]

Context

• Reporter: @annavik
• Source PR: Fix 2-digit year timestamp parsing, sync error reporting, and captures columns #1159
• Source comment: Fix 2-digit year timestamp parsing, sync error reporting, and captures columns #1159 (comment)
• Reported at: 2026-03-02T11:34:13Z

Summary

Ticks in generated sessions appear incorrect, especially for short sample sessions. This likely requires a joint backend + frontend change. Proposed direction: return one tick per capture instead of summary data (to evaluate for performance impact).

Requested action

• Investigate tick generation/rendering for session views.
• Evaluate feasibility and performance of returning 1 tick per capture.
• Coordinate changes across backend and frontend if needed.

Screenshots (from the original comment)

[mihow]

I suggest we switch from a line chart to a vertical bar chart, or at least explore it! The current visualization could also be improved to show what images have been processed or not #1093