Update page metadata (title, icon, move, archive, change space)

Setting workspaceId moves the page to another space the caller can access — the entire subtree moves with it and the page becomes a root of the target space unless the same request also names a parent inside it. A sidebar drag sends all three move fields at once (space, parent, position), so parentId is validated: - the parent must be a page the caller can see (404 otherwise — never a confirmation that an id exists in another org) - the parent must be in the space the page ends up in, so a page is never nested under a parent that space's readers cannot open (400) - the parent must not be the page itself or one of its own descendants (400) — a cycle detaches the whole branch from every root and it stops appearing in the tree `parentId: ""` clears the parent, putting the page at the top level of its space. `position` is a float, so a page can be dropped between two siblings by writing one row instead of renumbering the list.

curl -X PATCH "https://example.com/v1/pages/497f6eca-6276-4993-bfeb-53cbbbba6f08" \  -H "Content-Type: application/json" \  -d '{}'

{  "page": {    "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",    "workspaceId": "ef0efa32-d1c1-43d4-a5e2-fe7b4f00403c",    "parentId": "70850378-7d3c-4f45-91b7-942d4dfbbd43",    "title": "string",    "icon": "string",    "position": 0,    "createdBy": "25a02396-1048-48f9-bf93-102d2fb7895e",    "created": "2019-08-24T14:15:22Z",    "updated": "2019-08-24T14:15:22Z",    "archivedAt": "2019-08-24T14:15:22Z"  }}