Mark beta firmware versions with an amber Beta badge

Pre-release builds now carry a `beta` flag in each group's list.json.
Surface it in the UI: a small amber Beta pill (and amber card border)
next to the version on the landing list, in the version switcher, and
in the diff version-history panel, so betas are visually distinct from
stable releases while remaining fully diffable against historical builds.

src/app/os/keys/page.tsx

@@ -29,6 +29,7 @@ import { createEngine } from "@/lib/engine";
 import { getTopTokens, tokenizeKeys } from "@/lib/tokenizer";
 import type { OS } from "@/lib/types";
 import { cn } from "@/lib/utils";
+import { BetaBadge } from "@/components/beta-badge";
 
 function versionTag(os: OS) {
   return `${os.version}_${os.build}`;
@@ -198,8 +199,9 @@ function VersionHistoryPanel({
                           : "text-muted-foreground hover:text-foreground",
                       )}
                     >
-                      <span className="block truncate font-mono">
+                      <span className="flex items-center gap-1.5 truncate font-mono">
                         {version.version}
+                        {version.beta && <BetaBadge />}
                       </span>
                       <span
                         className={cn(

src/components/beta-badge.tsx

@@ -0,0 +1,20 @@
+import { cn } from "@/lib/utils";
+
+/**
+ * Small amber "Beta" pill shown next to pre-release firmware versions.
+ * Beta builds are surfaced by the `beta` flag in each group's list.json.
+ */
+export function BetaBadge({ className }: { className?: string }) {
+  return (
+    <span
+      className={cn(
+        "inline-flex items-center rounded-md border px-1.5 py-0.5 text-[10px] font-semibold uppercase leading-none tracking-wide",
+        "border-amber-400/50 bg-amber-50 text-amber-700",
+        "dark:border-amber-500/40 dark:bg-amber-950/40 dark:text-amber-300",
+        className,
+      )}
+    >
+      Beta
+    </span>
+  );
+}

src/components/oslist.tsx

@@ -8,6 +8,8 @@ import { useEffect, useMemo, useState } from "react";
 import { useQueryFilter } from "@/hooks/use-query-filter";
 import { dataURL } from "@/lib/env";
 import type { Group, OS } from "@/lib/types";
+import { cn } from "@/lib/utils";
+import { BetaBadge } from "./beta-badge";
 import { HeaderPortal } from "./header-portal";
 import { Button } from "./ui/button";
 import { Input } from "./ui/input";
@@ -309,13 +311,21 @@ export default function OSList() {
                         >
                           <Link
                             href={`/os/keys?os=${group.name}/${os.version}_${os.build}`}
-                            className="block p-3 border border-border rounded-lg hover:border-foreground/20 transition-colors hover:bg-accent/50"
+                            className={cn(
+                              "block p-3 border rounded-lg transition-colors hover:bg-accent/50",
+                              os.beta
+                                ? "border-amber-400/50 hover:border-amber-500/70 dark:border-amber-500/40"
+                                : "border-border hover:border-foreground/20",
+                            )}
                           >
                             <div className="text-xs text-muted-foreground mb-1 truncate">
                               {os.name}
                             </div>
-                            <div className="flex justify-between items-center">
-                              <span className="font-medium">{os.version}</span>
+                            <div className="flex justify-between items-center gap-2">
+                              <span className="font-medium flex items-center gap-1.5">
+                                {os.version}
+                                {os.beta && <BetaBadge />}
+                              </span>
                               <span className="text-xs text-muted-foreground font-mono">
                                 {os.build}
                               </span>
@@ -339,14 +349,20 @@ export default function OSList() {
                             >
                               <Link
                                 href={`/os/keys?os=${group.name}/${os.version}_${os.build}`}
-                                className="block p-3 border border-border rounded-lg hover:border-foreground/20 transition-colors hover:bg-accent/50"
+                                className={cn(
+                                  "block p-3 border rounded-lg transition-colors hover:bg-accent/50",
+                                  os.beta
+                                    ? "border-amber-400/50 hover:border-amber-500/70 dark:border-amber-500/40"
+                                    : "border-border hover:border-foreground/20",
+                                )}
                               >
                                 <div className="text-xs text-muted-foreground mb-1 truncate">
                                   {os.name}
                                 </div>
-                                <div className="flex justify-between items-center">
-                                  <span className="font-medium">
+                                <div className="flex justify-between items-center gap-2">
+                                  <span className="font-medium flex items-center gap-1.5">
                                     {os.version}
+                                    {os.beta && <BetaBadge />}
                                   </span>
                                   <span className="text-xs text-muted-foreground font-mono">
                                     {os.build}

src/components/version-switcher.tsx

@@ -13,6 +13,7 @@ import { ChevronDown, Check } from "lucide-react";
 
 import type { OS } from "@/lib/types";
 import { withBase, basePath, dataURL } from "@/lib/env";
+import { BetaBadge } from "@/components/beta-badge";
 
 function compareVersion(a: string, b: string) {
   const l1 = a.split(".").map(Number);
@@ -83,11 +84,12 @@ export function VersionSwitcher({ currentOs }: { currentOs: string }) {
           {loading ? (
             "Loading..."
           ) : currentVersion ? (
-            <span>
+            <span className="flex items-center gap-1.5">
               {currentVersion.version}{" "}
               <span className="text-muted-foreground text-xs">
                 ({currentVersion.build})
               </span>
+              {currentVersion.beta && <BetaBadge />}
             </span>
           ) : (
             currentBuild
@@ -123,11 +125,12 @@ export function VersionSwitcher({ currentOs }: { currentOs: string }) {
                   isSelected ? "bg-accent" : ""
                 }`}
               >
-                <span className="font-mono">
+                <span className="font-mono flex items-center gap-1.5">
                   {os.version}{" "}
                   <span className="text-muted-foreground text-xs">
                     ({os.build})
                   </span>
+                  {os.beta && <BetaBadge />}
                 </span>
                 {isSelected && <Check className="h-4 w-4" />}
               </button>

src/lib/types.ts

@@ -3,6 +3,7 @@ export interface OS {
   build: string;
   version: string;
   devices: string[];
+  beta?: boolean;
 }
 
 export interface Group {