feat(pitch-deck): branded short links for magic URLs (pitch.breakpilot.ai/p/ab3xk2)

- New pitch_short_links table stores 6-char alphanumeric codes mapped to magic link tokens
- GET /p/[code] redirects to /auth/verify?token=... (302, validates expiry)
- All magic link generation points (invite, generate-link, resend) now create a short code
- Emails (invite + resend) use the short URL — less token-like, cleaner for spam filters
- Copy-link UI shows short URL prominently with full URL as fallback
- Migration 008 added to /api/admin/migrate

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

pitch-deck/app/api/admin/invite/route.ts

@@ -3,6 +3,7 @@ import pool from '@/lib/db'
 import { generateToken } from '@/lib/auth'
 import { requireAdmin, logAdminAudit } from '@/lib/admin-auth'
 import { sendMagicLinkEmail } from '@/lib/email'
+import { createShortLink } from '@/lib/short-links'
 import { checkRateLimit, RATE_LIMITS } from '@/lib/rate-limit'
 
 export async function POST(request: NextRequest) {
@@ -72,9 +73,10 @@ export async function POST(request: NextRequest) {
 
   const baseUrl = process.env.PITCH_BASE_URL || 'https://pitch.breakpilot.ai'
   const magicLinkUrl = `${baseUrl}/auth/verify?token=${token}`
+  const shortUrl = await createShortLink(token)
 
   if (send_email) {
-    await sendMagicLinkEmail(normalizedEmail, name || null, magicLinkUrl, greeting, message, closing, normalizedLang)
+    await sendMagicLinkEmail(normalizedEmail, name || null, shortUrl, greeting, message, closing, normalizedLang)
   }
 
   await logAdminAudit(
@@ -99,5 +101,6 @@ export async function POST(request: NextRequest) {
     email: normalizedEmail,
     expires_at: expiresAt.toISOString(),
     magic_link_url: magicLinkUrl,
+    short_url: shortUrl,
   })
 }