List Grants Mine

Aggregate grants by client_id, joining oauth_clients for the display name. Counts and last_used_at come from the union of access + refresh tokens; first_authorized_at from the earliest token's created_at.

Filters out:

• tokens with revoked_at IS NOT NULL
• access tokens past their expires_at (refresh tokens with future expires_at keep the grant alive even if access is stale)
• clients with revoked_at set on oauth_clients (the whole client was disabled at the platform level)

Response shape::

{
  "grants": [
    {
      "client_id": "...",
      "client_name": "...",
      "scopes": ["mcp:read", ...],
      "active_access_tokens": <int>,
      "active_refresh_tokens": <int>,
      "last_used_at": "<ISO|null>",
      "first_authorized_at": "<ISO>"
    },
    ...
  ]
}