[DEPRECATED — use /v1/bars] Aggregated close history for a symbol — interval ∈ {1d, 1h}.

Dispatch to the per-interval handler. The handler is the Module Interface; per-interval helpers are Deep Modules hiding the interval-specific policy + storage shape.

DEPRECATED in favour of /v1/bars (C4). This endpoint retains the legacy close-only series[] wire shape for backward compatibility. Deprecation + Sunset + Link headers are injected on every 200 response (and on 403 plan_gated, where the caller may need to upgrade before migrating). The sunset DATE is founder-controlled (see config prices_history_sunset_date) — NOT hardcoded here.