Replace Bad Instance of databaseTiny.find()

[thehabes]

Closes #471

Summary

• Fix databaseTiny.find({_id}) in updateLayerAndProject() — replaced with fetch(page.id) pattern matching Page.js:183-205. The old call had two compounding bugs:
  1. find({_id}) fails collection resolution — determineDataType() cannot identify a type from {_id} alone, so resolveCollection() returns null and the driver throws.
  2. find() returns an array — even if resolution worked, the code treated the result as a single document, setting .partOf on an array.
• Correct smoke test — changed expected status from 400 to 401 for unauthenticated /my/profile requests.

Changes

File	Change
utilities/shared.js:87-112	Replace databaseTiny.find() with fetch(page.id) + error handling + response body validation
__tests__/smoke.test.js:60-63	Fix expected status code 400 → 401

Why fetch(page.id) instead of fixing the find() call

The page IDs in this code path are already full RERUM URLs (filtered by .startsWith(process.env.RERUMIDPREFIX) on line 85). Fetching by URL is the established pattern throughout the codebase (Page.js:183, Page.js:82) and avoids both the collection resolution issue and the array-vs-document issue entirely. No new dependencies — fetch is native in Node 18+.