Add issue change history and daily issue stats

Issue changes are recorded per field in the issue_change table, in the same
transaction as the issue itself. The new history module exposes:
- GET /api/issues/:issueId/history — change timeline grouped by save
- GET /api/issues/stats/daily — created, status transitions and status
  snapshot per day, with time zone support

The migration backfills history for existing issues. Setting a field to its
current value no longer bumps updatedAt or emits issue.updated.

src/modules/issue/application/use-cases/update-issue/update-issue.use-case.ts

@@ -57,7 +57,7 @@ export class UpdateIssueUseCase {
       issue.updateDueDate(command.dueDate);
     }
 
-    await this.issueRepository.update(issue);
+    await this.issueRepository.update(issue, command.userId);
     const dto = await this.issueUserExpander.expand(issue);
 
     if (issue.assignee) {