Fix issues tree view stuck empty until git commit

[Copilot]

The Issues panel could get permanently stuck empty on startup because setIssues() only fired _onDidChangeIssueData on the success path. If getIssues() threw (e.g. transient network error), the promise rejected silently, the tree data provider was never notified, and no subsequent refresh was triggered. A git commit would unstick it by triggering updateRepository() → setIssueData() which would retry the fetch.

Changes

• setIssues() — Replaced new Promise(async executor) anti-pattern with proper async/await. Errors now resolve with undefined instead of rejecting, and the change event fires in a finally block:

private async setIssues(folderManager, query): Promise<IssueItem[] | undefined> {
    try {
        const issues = await folderManager.getIssues(query, ...);
        return issues?.items.map(...);
    } catch {
        return undefined;
    } finally {
        this._onDidChangeIssueData.fire();
    }
}

• setIssueData() — Added _onDidChangeIssueData.fire() at the end as a guaranteed final refresh signal after all queries are processed, covering the edge case where _queries is empty or all per-query fires were somehow missed.

• Tests — Added coverage for: event fires on getIssues error, event fires twice per setIssueData call (per-query + final), and issueCollection promises resolve rather than reject on error.