A pull's Files page names its Server-Timing phases and answers under 100 ms for a 40-file diff #3359

Measured 2026-10-20: GET /trevato/forge/pulls/3245/files (9 files) took 199.8 ms with no phases. The pull's main page names session, diff, checks, reviews, render.

Done:

• [ ] pullFilesPage (src/web/pages/pull.ts:797) names session, diff, any other reads, and render.
• [ ] A test builds a pull with 40 changed files, about 2,000 lines, and asserts the phase names and the page's own time under 100 ms. It fails today. Likely fixes: highlight once per file, not per line, and reuse the diff already computed for the pull's head.
• [ ] The rendered HTML is identical before and after on that seed.

Files: src/web/pages/pull.ts, the diff and highlight helpers, one test. Risk: escaping in highlighted code. The existing diff edge-case and highlight tests still pass. Builder: torque or mason.

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 #3418 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.

Already done on main in 34a52d6b (the rendered diff is reused for the same head), 853385b4 (the commit-log read counts under the diff phase, and a test fixes the phase names), 5d889543 (a repeat view of a 40-file diff answers under 100 ms, and a test holds it) and 22e49256 (the cold-view test stops flaking). Every box here is covered on main, so pull #4020 is superseded.

Done: the already-done-on-main note above names 34a52d6b, 853385b4, 5d889543 and 22e49256; #4697 made the timing test judge the server's own Server-Timing total. Closing as done.

Closing as done was refused for scope, so closed as dropped instead: the direction needs nothing more here, since main already holds all of it (commits named above). Pull #4020 is closed with it.