Drop the dead url fields that broke every invocation

[iHiD]

Production is currently failing every request. Merging this immediately.

#16 removed const baseUrl but left the url: fields that reference it, so rawPathToScreenshotData throws ReferenceError: baseUrl is not defined. That call is the first thing the handler does — before the S3 cache check — so even requests that would have been served from cache fail.

url was only read by the Chrome renderer, so it should have gone with it in #16. My mistake.

Verified by actually invoking the handler

/profiles/ihid.jpg                       -> 200 (image)   # S3 cache hit, full path works
/tracks/ruby/.../ihid-1720000000.jpg     -> 500 fetch failed   # can't reach internal ALB locally, as expected
/nonsense                                -> 500 Could not map raw path

Why nothing caught it

Worth recording, because every check I ran was blind to it:

• node --check parses, it doesn't resolve identifiers
• The 45 unit tests cover the renderers and tokenizer, not index.js
• dev/render.js calls generate() directly and never goes through the handler
• My grep was for baseUrl =, which matched the declaration and not the two uses

The gap is that nothing exercises the handler. A test that calls exports.handler with each path shape would have caught this in a second, and would also have caught the two Dockerfile omissions if it ran in CI against the built image.