feat(web): add Peer Card Seed Kits

Adds a /seed-kits page where users can author named "kits" of card
lines (e.g. "Personal core", "Work context") and one-click apply them
to any peer across any registered instance. Removes the chore of
manually re-typing the same identity facts into multiple agents.

Built-in starter kits are read-only but forkable. User kits live in
localStorage. The apply flow shows a side-by-side merge preview that
dedupes by the line's prefix (text before the first ":"), so applying
a kit with "Name: Ben Sheridan-Edwards" to a peer whose card already
has "Name: Ben" replaces the line rather than duplicating it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/web/src/components/layout/Sidebar.tsx

@@ -8,6 +8,7 @@ import {
 	ChevronsUpDown,
 	Eye,
 	EyeOff,
+	Layers,
 	LayoutDashboard,
 	Lightbulb,
 	MessageSquare,
@@ -29,6 +30,7 @@ import { COLOR } from "@/lib/constants";
 const TOP_NAV = [
 	{ to: "/" as const, label: "Dashboard", icon: LayoutDashboard, exact: true },
 	{ to: "/workspaces" as const, label: "Workspaces", icon: Boxes, exact: false },
+	{ to: "/seed-kits" as const, label: "Seed Kits", icon: Layers, exact: false },
 	{ to: "/settings" as const, label: "Settings", icon: Settings, exact: false },
 ];