ui: apply interface polish from design article review

- Add global font smoothing (antialiased) to body
- Add tabular-nums to all numeric displays: MetricCard values, Costs page,
  AgentDetail token/cost grids and tables, IssueDetail cost summary,
  Companies page budget display
- Replace markdown image hard border with subtle inset box-shadow overlay
- Replace all animate-ping status dots with calmer animate-pulse across
  AgentDetail, IssueDetail, Agents, sidebar, kanban, issues list, and
  active agents panel

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

ui/src/pages/IssueDetail.tsx

@@ -565,7 +565,7 @@ export function IssueDetail() {
           {hasLiveRuns && (
             <span className="inline-flex items-center gap-1.5 rounded-full bg-cyan-500/10 border border-cyan-500/30 px-2 py-0.5 text-[10px] font-medium text-cyan-600 dark:text-cyan-400 shrink-0">
               <span className="relative flex h-1.5 w-1.5">
-                <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-cyan-400 opacity-75" />
+                <span className="animate-pulse absolute inline-flex h-full w-full rounded-full bg-cyan-400 opacity-75" />
                 <span className="relative inline-flex rounded-full h-1.5 w-1.5 bg-cyan-400" />
               </span>
               Live
@@ -901,7 +901,7 @@ export function IssueDetail() {
               {!issueCostSummary.hasCost && !issueCostSummary.hasTokens ? (
                 <div className="text-xs text-muted-foreground">No cost data yet.</div>
               ) : (
-                <div className="flex flex-wrap gap-3 text-xs text-muted-foreground">
+                <div className="flex flex-wrap gap-3 text-xs text-muted-foreground tabular-nums">
                   {issueCostSummary.hasCost && (
                     <span className="font-medium text-foreground">
                       ${issueCostSummary.cost.toFixed(4)}