Fill the remaining gaps: badge upload, radio tools, VPN, writeable boxes

Built the admin tools previously listed as missing:
- Badge upload (/admin/badges): uploads a <code>.gif into the emulator's
  badge dir via BADGE_UPLOAD_DIR (node:fs); validated code/type/size,
  logged. Made configurable rather than skipped.
- Radio tools: /admin/radio/api-keys (CRUD, server-generated keys),
  /admin/radio/autodj (Auto-DJ playlist CRUD), /admin/radio/embed (embed
  snippet generator), /admin/radio/points (points settings),
  /admin/radio/monitoring (live stream/now-playing/listeners status).
  radio_api_keys + radio_auto_dj_playlist already had real columns.
- /admin/vpn: VPN/proxy detection config (block toggle + provider + key),
  complementing /admin/ip's raw blacklist.
- Writeable boxes: new website_writeable_boxes table (model + migration
  0006) + /admin/writeable-boxes CRUD; active boxes render on the public
  home page. env: BADGE_UPLOAD_DIR.

Verified live (prod, amx_test): all 8 pages render with real data; a test
writeable box appeared on the public home and was reverted. tsc 0,
vitest 49/49, next build 0 (7 new admin routes).

src/actions/admin-badge-upload.ts

@@ -0,0 +1,66 @@
+"use server";
+
+import path from "node:path";
+import { writeFile } from "node:fs/promises";
+import { redirect } from "next/navigation";
+import { requireStaff } from "@/lib/admin/guard";
+import { logStaffActivity } from "@/lib/services/staff-activity";
+
+// Writes a badge image to the configured emulator badge directory. The path is
+// read from BADGE_UPLOAD_DIR so deployments can point it at their emulator's
+// `swf/c_images/album1584` (or equivalent) without code changes. AtomCMS only
+// ever stores .gif badges, so every upload is normalised to `<code>.gif`.
+
+const CODE_RE = /^[A-Za-z0-9_-]{1,64}$/;
+const MAX_BYTES = 1024 * 1024; // 1MB
+const ALLOWED_TYPES = new Set(["image/gif", "image/png"]);
+
+function back(param: string, value: string): never {
+  redirect(`/admin/badges?${param}=${encodeURIComponent(value)}`);
+}
+
+export async function uploadBadge(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+
+  const dir = process.env.BADGE_UPLOAD_DIR;
+  if (!dir) {
+    back("error", "Badge upload directory not configured");
+  }
+
+  const code = String(formData.get("code") ?? "").trim();
+  if (!CODE_RE.test(code)) {
+    back("error", "Invalid badge code (use A-Z, 0-9, _ or -, max 64 chars)");
+  }
+
+  const file = formData.get("file");
+  if (!(file instanceof File)) {
+    back("error", "No file uploaded");
+  }
+
+  if (file.size === 0) {
+    back("error", "Uploaded file is empty");
+  }
+  if (file.size > MAX_BYTES) {
+    back("error", "File too large (max 1MB)");
+  }
+  if (!ALLOWED_TYPES.has(file.type)) {
+    back("error", "File must be a GIF or PNG image");
+  }
+
+  try {
+    const buffer = Buffer.from(await file.arrayBuffer());
+    const target = path.join(dir, `${code}.gif`);
+    await writeFile(target, buffer);
+  } catch {
+    back("error", "Could not write the badge file to disk");
+  }
+
+  await logStaffActivity({
+    staffId: staff.id,
+    action: "badge_upload",
+    description: `Uploaded badge image "${code}.gif"`,
+    targetType: "badge",
+  });
+
+  redirect(`/admin/badges?uploaded=${encodeURIComponent(code)}`);
+}