UI: URL-based tab routing, ActivityRow extraction, and agent detail redesign

Switch agents, issues, and approvals pages from query-param tabs to
URL-based routes (/agents/active, /issues/backlog, /approvals/pending).
Extract shared ActivityRow component used by both Dashboard and Activity
pages. Redesign agent detail overview with LatestRunCard showing live/
recent run status, move permissions toggle to Configuration tab, add
budget progress bar, and reorder tabs (Runs before Configuration).
Dashboard now counts idle agents as active and shows "Recent Tasks"
instead of "Stale Tasks". Remove unused MyIssues page and sidebar link.

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

server/src/services/dashboard.ts

@@ -52,7 +52,10 @@ export function dashboardService(db: Db) {
         error: 0,
       };
       for (const row of agentRows) {
-        agentCounts[row.status] = Number(row.count);
+        const count = Number(row.count);
+        // "idle" agents are operational — count them as active
+        const bucket = row.status === "idle" ? "active" : row.status;
+        agentCounts[bucket] = (agentCounts[bucket] ?? 0) + count;
       }
 
       const taskCounts: Record<string, number> = {