refactor(report): finish via playback, one file per run

Uses the Finish the app already has, and stops rewriting the whole
history every time a show ends.

- The Go button already reads "Finish" on the last event and calls stop
  (playbackControl.utils). Closing the run hangs off that instead of a
  second Finish button of its own, so POST /report/runs/finish and the
  button in the overview are both gone. The run indicator stays as the
  way the feature is found, now a passive status that opens the reports
  panel.
- Reports move from one file per project to a directory per project with
  one file per run. Finishing a show wrote the entire history back to
  disk, which grew with every show ever recorded; it now writes only the
  run that just ended. Deleting a run unlinks one file and deleting a
  project removes one directory.
- A report that cannot be read is skipped instead of taking the rest of
  the history with it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019nr3FbLbM8gB8Jm771YgTV

apps/client/src/common/api/report.ts

@@ -60,14 +60,6 @@ export async function fetchOpenRun(options?: RequestOptions): Promise<OpenRun |
   }
 }
 
-/**
- * HTTP request to finish the run in progress, which is what writes it to history
- */
-export async function finishRun(): Promise<void> {
-  await axios.post(`${reportUrl}/runs/finish`);
-  await ontimeQueryClient.invalidateQueries({ queryKey: REPORT });
-}
-
 export async function renameRun(id: string, label: string): Promise<ShowRun> {
   const res = await axios.patch(`${reportUrl}/runs/${id}`, { label });
   await ontimeQueryClient.invalidateQueries({ queryKey: REPORT });