feat(curation): auto-curation after crawl + quality messaging

Automate curation:
- Add runPostCrawlCuration() to DB queries — runs after every
  full and incremental crawl (classify, dedup, category counts)
- No more need for manual curate.mjs runs after each crawl

Quality messaging:
- Homepage stats label: "Skills" → "Curated Skills" (en/fa)
- Add curation note: "deduplicated and quality-filtered from X+ repos"
- Update fallback counts from 172K to 16K across all touchpoints
  (BetaBanner, getting-started prompts, email templates)
- getting-started skill count query now uses browse-ready filter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/lib/email-templates.ts

@@ -220,12 +220,12 @@ export function buildWelcomeEmail(locale: Locale, username: string, email?: stri
   const dir = getDir(locale);
   const align = getAlign(locale);
 
-  // Format skill count: dynamic if provided, fallback to "172,000+"
+  // Format skill count: dynamic if provided, fallback to "16,000+"
   const skillCountStr = totalSkillCount
     ? (locale === 'fa'
       ? totalSkillCount.toLocaleString('fa-IR')
       : totalSkillCount.toLocaleString('en-US'))
-    : (locale === 'fa' ? '۱۷۲,۰۰۰' : '172,000');
+    : (locale === 'fa' ? '۱۶,۰۰۰' : '16,000');
 
   const body = `
     <h1 style="margin: 0 0 16px 0; color: ${COLORS.text}; font-size: 24px; text-align: ${align};">