fix(issue): Replace stopwatch toggle with explicit start/stop actions (#34818)

This PR fixes a state de-synchronization bug with the issue stopwatch,
it resolves the issue by replacing the ambiguous `/toggle` endpoint
with two explicit endpoints: `/start` and `/stop`.

- The "Start timer" button now exclusively calls the `/start` endpoint.
- The "Stop timer" button now exclusively calls the `/stop` endpoint.

This ensures the user's intent is clearly communicated to the server,
eliminating the state inconsistency and fixing the bug.

---------

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/features/stopwatch.ts

@@ -134,7 +134,7 @@ function updateStopwatchData(data: any) {
     const {repo_owner_name, repo_name, issue_index, seconds} = watch;
     const issueUrl = `${appSubUrl}/${repo_owner_name}/${repo_name}/issues/${issue_index}`;
     document.querySelector('.stopwatch-link')?.setAttribute('href', issueUrl);
-    document.querySelector('.stopwatch-commit')?.setAttribute('action', `${issueUrl}/times/stopwatch/toggle`);
+    document.querySelector('.stopwatch-commit')?.setAttribute('action', `${issueUrl}/times/stopwatch/stop`);
     document.querySelector('.stopwatch-cancel')?.setAttribute('action', `${issueUrl}/times/stopwatch/cancel`);
     const stopwatchIssue = document.querySelector('.stopwatch-issue');
     if (stopwatchIssue) stopwatchIssue.textContent = `${repo_owner_name}/${repo_name}#${issue_index}`;