Meta aggregate dashboard payload

Everything the portal's Meta dashboard header renders, in one call: the connected Instagram account (with follower / media counts and recent engagement), the Page, the ad account (with its currency and account status), the Business Manager, plus counts of recent own and tagged Instagram media.

Where /meta-ads/status is a database read, this fans out across several Graph edges — so it is served stale-while-revalidate from the same Valkey cache the portal uses (fresh under 5 minutes, usable-but-refreshing under 30, rebuilt inline only when cold), and invalidated immediately by any connection change. Every sub-object is open-schema: new fields can appear without a breaking change, and a sub-fetch that fails comes back as an empty object rather than failing the call. Single shop only.