feat(skills): add registry doctor diagnostics and docs

src/cli/doctor.ts

@@ -422,6 +422,61 @@ const checkSkills: Check = async (ctx) => {
   }
 };
 
+function toRegistrySource(value: string): { type: 'file'; path: string } | { type: 'url'; url: string } | null {
+  const trimmed = value.trim();
+  if (!trimmed) {
+    return null;
+  }
+  if (trimmed.startsWith('https://')) {
+    return { type: 'url', url: trimmed };
+  }
+  if (trimmed.startsWith('http://')) {
+    return null;
+  }
+  return { type: 'file', path: trimmed };
+}
+
+const checkSkillsRegistry: Check = async (ctx) => {
+  if (!ctx.config) {
+    return { status: 'skip', label: 'Skills registry', detail: '(config invalid)' };
+  }
+
+  const configured = ctx.config.skills.registry_source?.trim() || process.env.FLYNN_SKILLS_REGISTRY_SOURCE?.trim() || '';
+  if (!configured) {
+    return {
+      status: 'warn',
+      label: 'Skills registry',
+      detail: 'registry discovery unconfigured (set skills.registry_source or FLYNN_SKILLS_REGISTRY_SOURCE)',
+    };
+  }
+
+  const source = toRegistrySource(configured);
+  if (!source) {
+    return {
+      status: 'fail',
+      label: 'Skills registry',
+      detail: `invalid registry source '${configured}' (use local path or https:// URL)`,
+    };
+  }
+
+  try {
+    const { loadSkillRegistryCatalog } = await import('../skills/index.js');
+    const catalog = await loadSkillRegistryCatalog(source);
+    const sourceLabel = source.type === 'file' ? source.path : source.url;
+    return {
+      status: 'pass',
+      label: 'Skills registry',
+      detail: `loaded ${catalog.skills.length} entr${catalog.skills.length === 1 ? 'y' : 'ies'} from ${sourceLabel}`,
+    };
+  } catch (err) {
+    return {
+      status: 'fail',
+      label: 'Skills registry',
+      detail: err instanceof Error ? err.message : String(err),
+    };
+  }
+};
+
 const checkTailscale: Check = async (ctx) => {
   if (!ctx.config?.server?.tailscale?.serve) {
     return { status: 'skip', label: 'Tailscale Serve', detail: '(not enabled)' };
@@ -533,6 +588,7 @@ const allChecks: Check[] = [
   checkGmail,
   checkMcpServers,
   checkSkills,
+  checkSkillsRegistry,
   checkTailscale,
 ];