fix: accept numeric-leading skill names

package.json

@@ -13,6 +13,7 @@
   ],
   "scripts": {
     "build": "tsc",
+    "test": "node --import tsx --test test/portable-name-validation.test.ts",
     "dev": "tsx src/cli.ts",
     "prepublishOnly": "npm run build",
     "clean": "rm -rf dist"

src/adapters/portable.ts

@@ -107,11 +107,11 @@ export class PortableAdapter implements Adapter {
     if (!ir.identity.name) {
       issues.push({ severity: 'error', field: 'identity.name', message: 'name is required' });
     }
-    if (!/^[a-z][a-z0-9-]*$/.test(ir.identity.name)) {
+    if (!/^[a-z0-9][a-z0-9-]*$/.test(ir.identity.name)) {
       issues.push({
         severity: 'error',
         field: 'identity.name',
-        message: 'name must be lowercase a-z + hyphens',
+        message: 'name must be lowercase a-z, 0-9 + hyphens',
       });
     }
     if (!ir.identity.description.full) {

src/ir.ts

@@ -17,7 +17,7 @@ export interface SkillIR {
 }
 
 export interface Identity {
-  /** Skill name. lowercase a-z + hyphens. Must match directory name. */
+  /** Skill name. Lowercase letters, numbers, and hyphens. Must match directory name. */
   name: string;
 
   description: {

test/portable-name-validation.test.ts

@@ -0,0 +1,31 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { PortableAdapter } from '../src/adapters/portable.js';
+import { emptyIR } from '../src/ir.js';
+
+const adapter = new PortableAdapter();
+
+function validateName(name: string) {
+  const ir = emptyIR(name);
+  ir.identity.description.full = 'A test skill.';
+  return adapter.validate(ir);
+}
+
+test('accepts numeric-leading portable skill names such as 4up', () => {
+  const result = validateName('4up');
+
+  assert.equal(result.ok, true);
+  assert.deepEqual(result.issues, []);
+});
+
+test('continues rejecting invalid portable skill names', () => {
+  for (const name of ['Uppercase', 'has_underscore', 'has space', '']) {
+    const result = validateName(name);
+
+    assert.equal(result.ok, false, `expected ${JSON.stringify(name)} to be rejected`);
+    assert.ok(
+      result.issues.some((issue) => issue.field === 'identity.name'),
+      `expected an identity.name issue for ${JSON.stringify(name)}`
+    );
+  }
+});