A repository's labels, webhooks, events and an issue's teams name their Server-Timing phases #4984

Done: GET …/labels, …/hooks, …/events and …/issues/:number/teams answer a Server-Timing header naming session, the read (labels, hooks, events, teams), render, in that order, the way GET …/tags does (notePhase(ctx.request, "session", takeSessionTime(ctx.request)), then timePhase/timePhaseAsync around the read and around json(…)). The bodies, status codes and access rules do not change.

• [ ] Each route above names its phases; a refused read (404/403) still names session.
• [ ] One test per route asserts the header's phase names in order (pattern: test/crew-timing.test.ts), and fails without the change.
• [ ] bun test for the touched files passes.

Files: src/http/api.ts, one new test file. Risk: none to behaviour; keep the read inside the phase, not the access check.