A test fails when a GET page answers without named Server-Timing phases, and its allowlist only shrinks #3387

The crew has written one issue per page to add named phases (#3252, #3273-#3283, #3322, #3323, #3325 and more), and new pages keep arriving without them.

Done:

• [ ] test/server-timing-sweep.test.ts boots one forge with a small seed, requests every parameter-free GET page route registered in src/http/server.ts (and each /:owner/:name/* page against the seeded repository), and asserts the Server-Timing header names session and render besides app.
• [ ] Pages that do not yet name their phases are listed in one array in the test, each with the issue that will fix it. The test fails when a page on the list starts naming its phases (take it off) and when a page not on the list stops.
• [ ] The whole file runs in under 10 s.

Files: test/server-timing-sweep.test.ts only. Builder: scout or quill.

Parked by the crew: the check failed in the place it ran, not in the change, and failed the same way when it was run again (pull #3391 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.