Auto-generate argument hint with all commands grouped by category

The static "[command] [target]" hint didn't help users discover available
commands. The build now reads command-metadata.json and groups commands
by category (from SKILL_CATEGORIES) with middle-dot separators for
natural line-breaking in the prompt bar.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/lib/sub-pages-data.js

@@ -43,7 +43,7 @@ const EXCLUDED_SKILLS = new Set([
  * Mirrors public/js/data.js commandCategories. Validated below: the
  * generator fails if any user-invocable skill is missing from this map.
  */
-const SKILL_CATEGORIES = {
+export const SKILL_CATEGORIES = {
   // CREATE - build something new
   impeccable: 'create',
   craft: 'create',

scripts/lib/transformers/factory.js

@@ -1,5 +1,6 @@
 import path from 'path';
 import { cleanDir, ensureDir, writeFile, generateYamlFrontmatter, replacePlaceholders } from '../utils.js';
+import { SKILL_CATEGORIES, CATEGORY_ORDER } from '../sub-pages-data.js';
 
 /**
  * Map from frontmatter field name to extraction spec.
@@ -86,6 +87,24 @@ export function createTransformer(config) {
         if (val) frontmatterObj[spec.yamlKey] = val;
       }
 
+      // Replace {{command_hint}} in argument-hint with command names from metadata,
+      // grouped by category with middle dots between groups for natural line-breaking.
+      if (frontmatterObj['argument-hint']?.includes('{{command_hint}}')) {
+        const metaScript = skill.scripts?.find(s => s.name === 'command-metadata.json');
+        if (metaScript) {
+          const commands = Object.keys(JSON.parse(metaScript.content));
+          // Derive groups from SKILL_CATEGORIES, excluding the parent skill name
+          const grouped = CATEGORY_ORDER
+            .map(cat => commands.filter(c => SKILL_CATEGORIES[c] === cat).join('|'))
+            .filter(Boolean)
+            .join(' · ');
+          frontmatterObj['argument-hint'] = frontmatterObj['argument-hint'].replace(
+            '{{command_hint}}',
+            grouped
+          );
+        }
+      }
+
       const frontmatter = generateYamlFrontmatter(frontmatterObj);
 
       // Build body