SPA ROUTE AUDIT PRACTICE LAB — illustrative only

Requirements: Python 3; a browser. No packages or network downloads.
Extract the ZIP into a new folder. Open a terminal in that folder and run:
    python server.py
Then visit http://localhost:8769/products/tea-set/
The server binds only to 127.0.0.1. Stop with Ctrl+C.

This is plain browser JavaScript, not React. It models response/rendering
states for practicing the five-route audit on a local computer. It contains
intentional missing-route and API failure handling defects. Do not deploy it.

The unknown route returns 200 with a not-found message and no noindex.
The removed route returns 410. The API-down page returns 200 while its API
returns 503. The filtered route uses the base collection canonical.
Compare document and API requests separately. Test direct visits and links.
No Googlebot, indexing, rankings, or real client outcomes are measured.
