feat(21-02): add Skeleton component and skeleton loading states for dashboard + inbox

Create reusable Skeleton component with animate-pulse styling. Replace
plain "Loading..." text with structured skeleton placeholders matching
card layouts in InitiativeList and inbox page.

packages/web/src/components/InitiativeList.tsx

@@ -1,5 +1,7 @@
 import { AlertCircle, Plus } from "lucide-react";
 import { Button } from "@/components/ui/button";
+import { Card } from "@/components/ui/card";
+import { Skeleton } from "@/components/Skeleton";
 import { InitiativeCard } from "@/components/InitiativeCard";
 import { trpc } from "@/lib/trpc";
 
@@ -28,8 +30,19 @@ export function InitiativeList({
   // Loading state
   if (initiativesQuery.isLoading) {
     return (
-      <div className="flex items-center justify-center py-12 text-muted-foreground">
-        Loading initiatives...
+      <div className="space-y-3">
+        {Array.from({ length: 3 }).map((_, i) => (
+          <Card key={i} className="p-4">
+            <div className="flex flex-col gap-3 md:flex-row md:items-center md:justify-between">
+              <Skeleton className="h-5 w-48" />
+              <div className="flex flex-1 items-center gap-4">
+                <Skeleton className="h-5 w-16" />
+                <Skeleton className="h-2 w-32" />
+                <Skeleton className="h-4 w-24" />
+              </div>
+            </div>
+          </Card>
+        ))}
       </div>
     );
   }

packages/web/src/components/Skeleton.tsx

@@ -0,0 +1,11 @@
+import { cn } from "@/lib/utils";
+
+interface SkeletonProps {
+  className?: string;
+}
+
+export function Skeleton({ className }: SkeletonProps) {
+  return (
+    <div className={cn("animate-pulse rounded-md bg-muted", className)} />
+  );
+}

packages/web/src/routes/inbox.tsx

@@ -1,7 +1,9 @@
 import { useState } from "react";
-import { createFileRoute } from "@tanstack/react-router";
+import { createFileRoute, Link } from "@tanstack/react-router";
 import { AlertCircle } from "lucide-react";
 import { Button } from "@/components/ui/button";
+import { Card } from "@/components/ui/card";
+import { Skeleton } from "@/components/Skeleton";
 import { trpc } from "@/lib/trpc";
 import { InboxList } from "@/components/InboxList";
 import { QuestionForm } from "@/components/QuestionForm";
@@ -89,8 +91,32 @@ function InboxPage() {
   // Loading state
   if (agentsQuery.isLoading && messagesQuery.isLoading) {
     return (
-      <div className="flex items-center justify-center py-12 text-muted-foreground">
-        Loading inbox...
+      <div className="space-y-4">
+        {/* Skeleton header */}
+        <div className="flex items-center justify-between">
+          <div className="flex items-center gap-2">
+            <Skeleton className="h-6 w-28" />
+            <Skeleton className="h-5 w-8 rounded-full" />
+          </div>
+          <Skeleton className="h-8 w-20" />
+        </div>
+        {/* Skeleton message rows */}
+        <div className="space-y-2">
+          {Array.from({ length: 4 }).map((_, i) => (
+            <Card key={i} className="p-4">
+              <div className="flex items-start justify-between gap-4">
+                <div className="min-w-0 flex-1">
+                  <div className="flex items-center gap-2">
+                    <Skeleton className="h-3 w-3 rounded-full" />
+                    <Skeleton className="h-4 w-32" />
+                  </div>
+                  <Skeleton className="mt-2 ml-5 h-3 w-full" />
+                </div>
+                <Skeleton className="h-3 w-16" />
+              </div>
+            </Card>
+          ))}
+        </div>
       </div>
     );
   }