VS-16 — Temporal Navigation #62

What to build

A period selector that controls which data snapshot the zone detail panel shows. Three granularities only, matching core.time_bucket on the backend. History uses bucket_id strings (e.g. "2026-07").

Time granularity (fixed — not open-ended)

MONTHLY — "2026-07"
BIMONTHLY — "2026-S2"
YEARLY — "2026"

Daily and weekly granularity do not exist in the backend — do not add them.

Acceptance criteria

• 3-option granularity toggle (Monthly / Bimonthly / Yearly)
• From/to range selection drives re-fetch of zone detail history
• Current period stored in mapStore.currentPeriod
• Current period label shown on map (e.g. "Juillet 2026")
• Zones with no data for a bucket show empty history — not an error

Blocked by

VS-14 Zone Selection + Ecological Detail Panel