Fix: The feeds were broken, and quietly. Both /feed.xml and /feed.json had been emitting a PHP…

The feeds were broken, and quietly. Both /feed.xml and /feed.json had been emitting a PHP warning ahead of the payload since they launched on 24 July — one line of HTML before the XML declaration, which is enough to make a feed unparseable for every reader that fetched it. The cause was a regular expression whose delimiter was # while the pattern itself contained a literal # (URL fragments), so it was read as ending early. Fixed, along with two link bugs it was hiding: an entry mentioning an asset path such as /assets/data/tools.json pointed at a page that does not exist, and single-segment pages were never linked at all. The reason a warning could reach you in the first place is the deeper fix: PHP was configured to print diagnostics into the page, which on a bad day means a server path and a stack of internals in the response body. Errors now go to a log file that is not reachable over HTTP, and never into what you receive. The feed test suite now asserts on what the feed prints, not just on what it returns — a warning in the body is a build failure from here on.