A running run page and app page drop the 5-second meta refresh and patch their status from /events #2873

Split from #2722. The log lines already stream over /events (#2843, #2854), but src/web/studio/run.ts:411 and src/web/studio/app.ts:514 still reload the whole page every 5 s while a run is unfinished.

Done looks like:

• [ ] Neither page sets refresh while running. The status, cost and verdict region carries data-live="run.*" (scoped to its repository) and swaps in place when the run changes state, and the log keeps streaming.
• [ ] When the run finishes, the region shows the final state without a reload.
• [ ] Test: an unfinished run's page has no <meta http-equiv="refresh"> and has the live region, and a finished one renders the same final state as before.

Files: src/web/studio/run.ts, src/web/studio/app.ts, a test under test/.