UI: Identity component, LiveRunWidget, issue identifiers, and UX improvements

Add Identity component (avatar + name) used across agent/issue displays. Add
LiveRunWidget for real-time streaming of active heartbeat runs on issue detail
pages via WebSocket. Display issue identifiers (PAP-42) instead of UUID
fragments throughout Issues, Inbox, CommandPalette, and detail pages.
Enhance CommentThread with re-open checkbox, Cmd+Enter submit, sorted display,
and run linking. Improve Activity page with richer formatting and filtering.
Update Dashboard with live metrics. Add reports-to agent link in AgentProperties.
Various small fixes: StatusIcon centering, CopyText ref init, agent detail
run-issue cross-links.

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

ui/src/components/Identity.tsx

@@ -0,0 +1,38 @@
+import { cn } from "@/lib/utils";
+import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
+
+type IdentitySize = "sm" | "default" | "lg";
+
+export interface IdentityProps {
+  name: string;
+  avatarUrl?: string | null;
+  initials?: string;
+  size?: IdentitySize;
+  className?: string;
+}
+
+function deriveInitials(name: string): string {
+  const parts = name.trim().split(/\s+/);
+  if (parts.length >= 2) return (parts[0][0] + parts[parts.length - 1][0]).toUpperCase();
+  return name.slice(0, 2).toUpperCase();
+}
+
+const textSize: Record<IdentitySize, string> = {
+  sm: "text-xs",
+  default: "text-sm",
+  lg: "text-sm",
+};
+
+export function Identity({ name, avatarUrl, initials, size = "default", className }: IdentityProps) {
+  const displayInitials = initials ?? deriveInitials(name);
+
+  return (
+    <span className={cn("inline-flex items-center gap-1.5", size === "lg" && "gap-2", className)}>
+      <Avatar size={size}>
+        {avatarUrl && <AvatarImage src={avatarUrl} alt={name} />}
+        <AvatarFallback>{displayInitials}</AvatarFallback>
+      </Avatar>
+      <span className={cn("truncate", textSize[size])}>{name}</span>
+    </span>
+  );
+}