Social-only slice of the digest — the CMO loop's input substrate.

Returns the social block from /ops/digest plus the relevant cost and PostHog totals needed to reason about per-channel ROI. The autonomous-CMO board agent reads this endpoint on its scheduled cycle (initial cadence: 12h, configurable via cron schedule on the Railway cmo-cron service).

Shape::

{
  "as_of_utc": "...",
  "window": "7d",
  "social": {
    "supply": {                       # from content_outbox.sqlite
      "configured": true,
      "window_days": 7,
      "channels": {
        "x":        {"queued":..., "published":..., "failed":..., ...},
        "linkedin": {...}, "reddit": {...}, "devto": {...},
        "bluesky":  {...}
      },
      "totals": {"queued":..., "published":..., "failed":...,
                 "rejected_editorial":..., "publish_rate": 0.xx}
    },
    "demand": {                       # from PostHog UTM breakdown
      "configured": true,
      "by_source": {"x": {"verify_button_click": N, ...}, ...}
    }
  },
  "cost": {...}
}

Auth: Bearer token from ETYMOLT_OPS_DIGEST_TOKEN (same gate as the parent /ops/digest endpoint).