Trim the eager countries chunk from 244 KB to 47 KB

src/lib/countries.ts imported the full iso-3166 package solely to build
a Set of valid ISO 3166-2 subdivision codes for validation. That dataset
(~5000 objects with names, parents, and tree structure) landed in the
eagerly-preloaded countries chunk because NoteContent, ComposeBox, and
campaign.ts all import from countries.ts on the critical path.

Ship only the subdivision code strings instead, generated at build time
into src/lib/subdivisionCodes.ts via scripts/gen-subdivision-codes.mjs.
iso-3166 moves to devDependencies since only the generator script needs
it now. The strict-validation contract (rejecting US-ZZ etc.) is
preserved.

package-lock.json

@@ -102,7 +102,6 @@
         "i18next": "^26.0.5",
         "i18next-browser-languagedetector": "^8.2.1",
         "idb": "^8.0.3",
-        "iso-3166": "^4.4.0",
         "lucide-react": "^1.8.0",
         "nostr-tools": "^2.13.0",
         "qr-scanner": "^1.4.2",
@@ -149,6 +148,7 @@
         "eslint-plugin-react-hooks": "^5.1.0-rc.0",
         "eslint-plugin-react-refresh": "^0.4.9",
         "globals": "^15.9.0",
+        "iso-3166": "^4.4.0",
         "jsdom": "^26.1.0",
         "postcss": "^8.4.47",
         "rollup-plugin-visualizer": "^7.0.1",
@@ -9333,6 +9333,7 @@
       "version": "4.4.0",
       "resolved": "https://registry.npmjs.org/iso-3166/-/iso-3166-4.4.0.tgz",
       "integrity": "sha512-I6ylkNQgxVh7cYADMUJpqBUdremGvyGZkDRSk9Cdic/ITBUemsllQnUeRpz7yDKyfgAXI9oPa5A9dia+7IXLqw==",
+      "dev": true,
       "license": "MIT",
       "funding": {
         "type": "github",

package.json

@@ -109,7 +109,6 @@
     "i18next": "^26.0.5",
     "i18next-browser-languagedetector": "^8.2.1",
     "idb": "^8.0.3",
-    "iso-3166": "^4.4.0",
     "lucide-react": "^1.8.0",
     "nostr-tools": "^2.13.0",
     "qr-scanner": "^1.4.2",
@@ -156,6 +155,7 @@
     "eslint-plugin-react-hooks": "^5.1.0-rc.0",
     "eslint-plugin-react-refresh": "^0.4.9",
     "globals": "^15.9.0",
+    "iso-3166": "^4.4.0",
     "jsdom": "^26.1.0",
     "postcss": "^8.4.47",
     "rollup-plugin-visualizer": "^7.0.1",

scripts/gen-subdivision-codes.mjs

@@ -0,0 +1,39 @@
+// Generate src/lib/subdivisionCodes.ts — the authoritative list of ISO 3166-2
+// subdivision codes, extracted from the `iso-3166` package.
+//
+// We ship only the code strings (~42 KB) instead of importing the full
+// `iso-3166` dataset (~244 KB of objects with names, parents, and tree
+// structure) into the critical-path bundle. The only thing the runtime needs
+// these for is validating that a `CC-XX` code is a real subdivision
+// (see src/lib/countries.ts `isValidSubdivisionCode`).
+//
+// Run with: node scripts/gen-subdivision-codes.mjs
+
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { iso31662 } from 'iso-3166';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const REPO_ROOT = path.resolve(__dirname, '..');
+const OUTPUT = path.join(REPO_ROOT, 'src/lib/subdivisionCodes.ts');
+
+const codes = [...new Set(iso31662.map((s) => s.code))].sort();
+
+const header = `// AUTO-GENERATED — do not edit by hand.
+//
+// The authoritative list of ISO 3166-2 subdivision codes, extracted from the
+// \`iso-3166\` package at build time. We ship only the code strings (~42 KB)
+// instead of importing the full \`iso-3166\` dataset (~244 KB of objects with
+// names, parents, and tree structure) into the critical-path bundle, since
+// the only thing the runtime needs these for is validating that a \`CC-XX\`
+// code is a real subdivision.
+//
+// Regenerate with: node scripts/gen-subdivision-codes.mjs
+
+`;
+
+const body = `export const SUBDIVISION_CODES: readonly string[] = ${JSON.stringify(codes)};\n`;
+
+fs.writeFileSync(OUTPUT, header + body);
+console.log(`Wrote ${path.relative(REPO_ROOT, OUTPUT)} (${codes.length} codes)`);

src/lib/countries.ts

@@ -1,8 +1,15 @@
-import { iso31662 } from 'iso-3166';
 import { getSubdivisionName, getSubdivisionWikipediaTitle } from './subdivisions';
+import { SUBDIVISION_CODES as SUBDIVISION_CODE_LIST } from './subdivisionCodes';
 
-/** Authoritative set of ISO 3166-2 subdivision codes for validation. */
-const SUBDIVISION_CODES = new Set(iso31662.map((s) => s.code));
+/**
+ * Authoritative set of ISO 3166-2 subdivision codes for validation.
+ *
+ * Backed by a build-time-generated code list (`subdivisionCodes.ts`) rather
+ * than importing the full `iso-3166` package, which would drag ~244 KB of
+ * subdivision objects into the critical-path bundle. Regenerate the list with
+ * `node scripts/gen-subdivision-codes.mjs`.
+ */
+const SUBDIVISION_CODES = new Set(SUBDIVISION_CODE_LIST);
 
 /** ISO 3166-1 alpha-2 country code to country name and flag emoji mapping. */
 export const COUNTRIES: Record<string, { name: string; flag: string }> = {