fix(web/store): restore the plugin cards' top padding, and capitalise platform names

Two things looked wrong in the store:

The cards had no space above the icon. `CardContent` zeroes its own top padding
(`pt-0`/`sm:pt-0`) because it normally sits under a `CardHeader` that supplies
it — but these cards have no header, so the top padding simply vanished while
the other three sides kept `p-card`. `p-card` does not undo it: `card` is a
custom `--spacing-*` token, which tailwind-merge does not recognise as a
spacing value and so never dedupes against `pt-0`, leaving the longhand to win.
Both header-less cards in this section now restore it explicitly, at both
breakpoints.

Platform chips read "windows" / "linux". Those are the catalog's platform
IDENTIFIERS (the index validator pins `linux | windows | macos`), which is right
for the wire and wrong on screen; the card now maps them to display names —
Linux, Windows, macOS. Proper nouns, so deliberately not routed through i18n.

Adds Store/StoreCard stories covering the padding, the platform labels, and the
installed / update / incompatible / blocked / external states, so the card can
be eyeballed without a host or a catalog.

web/src/sections/Store/Browse.tsx

@@ -127,6 +127,26 @@ export const BrowseTab: FC<{
 	);
 };
 
+/**
+ * The catalog stores platform IDENTIFIERS (`linux | windows | macos` — see the index
+ * validator); these are their display names. Proper nouns, so deliberately not routed
+ * through i18n, and `macos` is spelled the way Apple spells it.
+ */
+const PLATFORM_LABELS: Record<string, string> = {
+	linux: "Linux",
+	windows: "Windows",
+	macos: "macOS",
+};
+
+/**
+ * `CardContent` zeroes its top padding (`pt-0`/`sm:pt-0`) because it normally sits under a
+ * `CardHeader` that already supplies it — these cards have no header, so the top padding
+ * has to come back explicitly, at BOTH breakpoints. `p-card` alone does not do it: `card`
+ * is a custom `--spacing-*` token, which tailwind-merge does not recognise as a spacing
+ * value and therefore never dedupes against `pt-0`, leaving the longhand to win.
+ */
+const HEADERLESS_CARD_PADDING = "p-card pt-card sm:pt-card";
+
 /** One catalog entry. Blocked entries shout; incompatible ones grey out; neither can be installed. */
 export const StoreCard: FC<{ entry: StoreEntry; onInstall: () => void }> = ({
 	entry,
@@ -145,7 +165,9 @@ export const StoreCard: FC<{ entry: StoreEntry; onInstall: () => void }> = ({
 				!entry.compatible && !blocked && "opacity-60",
 			)}
 		>
-			<CardContent className="flex flex-1 flex-col gap-3 p-card">
+			<CardContent
+				className={cn("flex flex-1 flex-col gap-3", HEADERLESS_CARD_PADDING)}
+			>
 				<div className="flex items-start gap-3">
 					<span className="flex size-10 shrink-0 items-center justify-center rounded-md bg-primary/15">
 						<Icon className="size-5 text-foreground" />
@@ -173,7 +195,7 @@ export const StoreCard: FC<{ entry: StoreEntry; onInstall: () => void }> = ({
 				<div className="flex flex-wrap gap-1.5">
 					{entry.platforms.map((p) => (
 						<Badge key={p} variant="secondary" className="font-normal">
-							{p}
+							{PLATFORM_LABELS[p] ?? p}
 						</Badge>
 					))}
 				</div>

web/src/sections/Store/JobProgress.tsx

@@ -66,7 +66,7 @@ export const JobProgressCard: FC<{
 			className={failed ? "ring-2 ring-destructive/60" : undefined}
 			aria-live="polite"
 		>
-			<CardContent className="space-y-3 p-card">
+			<CardContent className="space-y-3 p-card pt-card sm:pt-card">
 				<div className="flex items-start gap-3">
 					{running ? (
 						<Spinner className="mt-0.5 size-5 shrink-0" />

web/src/stories/Store.stories.tsx

@@ -0,0 +1,91 @@
+import type { Meta, StoryObj } from "@storybook/react-vite";
+import type { StoreEntry } from "@/api/store";
+import { StoreCard } from "@/sections/Store/Browse";
+
+// The store catalog card, rendered straight from a fixture entry — it fetches nothing, so
+// the visuals (padding, platform labels, tier chip, blocked/incompatible states) can be
+// checked without a host or a catalog.
+
+const meta = {
+	title: "Store/StoreCard",
+	component: StoreCard,
+	parameters: { layout: "centered" },
+	args: { onInstall: () => {} },
+} satisfies Meta<typeof StoreCard>;
+
+export default meta;
+type Story = StoryObj<typeof meta>;
+
+const BASE: StoreEntry = {
+	id: "rom-manager",
+	pkg: "@punktfunk/plugin-rom-manager",
+	title: "ROM Manager",
+	description:
+		"Scans your ROM directories, maps them to emulators, fetches box art, and reconciles everything into the host game library as a provider.",
+	icon: "gamepad-2",
+	author: "unom",
+	homepage: "https://git.unom.io/unom/punktfunk-plugin-rom-manager",
+	license: "MIT OR Apache-2.0",
+	version: "0.3.2",
+	source: "unom official",
+	tier: "verified",
+	// The catalog stores lowercase platform IDENTIFIERS; the card renders display names.
+	platforms: ["linux", "windows"],
+	compatible: true,
+	update_available: false,
+};
+
+export const Default: Story = { args: { entry: BASE } };
+
+export const AllPlatforms: Story = {
+	args: { entry: { ...BASE, platforms: ["linux", "windows", "macos"] } },
+};
+
+export const SinglePlatform: Story = {
+	args: {
+		entry: {
+			...BASE,
+			id: "playnite",
+			pkg: "@punktfunk/plugin-playnite",
+			title: "Playnite",
+			description:
+				"Syncs your Playnite library into the host game library — every store and emulator Playnite manages, launched back through Playnite.",
+			icon: "library-big",
+			version: "0.2.0",
+			platforms: ["windows"],
+		},
+	},
+};
+
+export const Installed: Story = {
+	args: { entry: { ...BASE, installed_version: "0.3.2" } },
+};
+
+export const UpdateAvailable: Story = {
+	args: {
+		entry: { ...BASE, installed_version: "0.3.1", update_available: true },
+	},
+};
+
+export const Incompatible: Story = {
+	args: {
+		entry: {
+			...BASE,
+			compatible: false,
+			incompatible_reason:
+				"needs punktfunk host ≥ 0.16.0 (this host is 0.15.0)",
+		},
+	},
+};
+
+export const Blocked: Story = {
+	args: {
+		entry: { ...BASE, blocked: "withdrawn by the author (CVE-2026-1234)" },
+	},
+};
+
+export const External: Story = {
+	args: {
+		entry: { ...BASE, tier: "external", source: "community catalog" },
+	},
+};