Dashboard: "Burnbar Wrapped" monthly/yearly recap

[tangentlin]

Motivation

Burnbar's durable archive (the whole point of the app per ADR-006/007) makes it possible to look back over a month or year of usage — a Spotify-Wrapped-style animated recap would turn that historical data into a genuinely fun, shareable-feeling moment instead of just a chart to scroll through.

Proposal

A slide-through modal/view in the dashboard summarizing a completed period: biggest single day, top model, total spend/tokens, longest streak, etc., each stat presented as an animated "slide" (fade/slide transitions between stats, similar to Spotify Wrapped or GitHub's yearly recap).

Feasibility notes

• Pure read-time aggregation over existing archive data (DailyRecord/SessionRecord) — likely a new derive.ts function (e.g. deriveRecap(range)) plus a new dashboard view/modal, no new archive fields needed.
• Scope question to settle before implementation: auto-trigger (e.g. offer a recap when a month/year completes) vs. purely on-demand from the dashboard — recommend on-demand only for v1 to avoid unwanted interruptions, consistent with Burnbar's tray-only, non-intrusive posture.

Acceptance criteria

• Recap view accessible on-demand from the dashboard for a completed month or year.
• Presents at least: total spend, total tokens, top model, biggest day.
• Slide/stat transitions are animated, not a static summary card.
• No automatic/interruptive triggering in v1 (opt-in only).