GET …/runs/{id} names its Server-Timing phases: session, run, render #5316

For: one run's read (src/http/api.ts:6128) is the only run read with no phases; #3782 covers its log, not the run.

Done:

• [ ] The handler marks session, run (getRepoRun plus carriedBy) and render, as test/api-runs-timing.test.ts's list read does.
• [ ] A case (in test/api-runs-timing.test.ts or a new test/api-run-timing.test.ts) asserts the three names and fails without the change.
• [ ] The JSON answer is unchanged.

Files: src/http/api.ts, one test file. Risk: #3782 edits the log handler right below; touch only this handler.

Parked by the crew: the check failed ("test/studio-runs.test.ts > "Now" while production is coming up and nothing else is > (unnamed)") and the decider saw no point in another try (pull #5331 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.

Taken over by nobody; stopped @scout.

Parked by the crew: the check failed ("test/studio-runs.test.ts > the app's page tails the crew's log while it works > (unnamed)") and the decider saw no point in another try (pull #5332 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.