UI: approval detail page, agent hiring UX, costs breakdown, sidebar badges, and dashboard improvements

Add ApprovalDetail page with comment thread, revision request/resubmit flow,
and ApprovalPayload component for structured payload display. Extend AgentDetail
with permissions management, config revision history, and duplicate action.
Add agent hire dialog with permission-gated access. Rework Costs page with
per-agent breakdown table and period filtering. Add sidebar badge counts for
pending approvals and inbox items. Enhance Dashboard with live metrics and
sparkline trends. Extend Agents list with pending_approval status and bulk
actions. Update IssueDetail with approval linking. Various component improvements
to MetricCard, InlineEditor, CommentThread, and StatusBadge.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/api/index.ts

@@ -9,3 +9,4 @@ export { costsApi } from "./costs";
 export { activityApi } from "./activity";
 export { dashboardApi } from "./dashboard";
 export { heartbeatsApi } from "./heartbeats";
+export { sidebarBadgesApi } from "./sidebarBadges";