docs: add comprehensive code comments, update README and TASKS, create training and troubleshooting guides

- Add JSDoc comments to API routes and business logic functions
- Update README.md with Phase 2 status and deployment/production notes
- Enhance TASKS.md with estimated timelines and dependencies
- Create docs/STAFF_TRAINING.md for team onboarding
- Create docs/CLIENT_ONBOARDING.md for customer experience
- Create docs/OPERATIONAL_PROCEDURES.md for daily operations
- Create docs/TROUBLESHOOTING.md for common setup issues
- Fix TypeScript errors in hq/page.tsx

app/api/create-payment-intent/route.ts

@@ -4,6 +4,11 @@ import { supabaseAdmin } from '@/lib/supabase/client'
 
 const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!)
 
+/**
+ * @description Creates a Stripe payment intent for booking deposit (50% of service price, max $200)
+ * @param {NextRequest} request - Request containing booking details
+ * @returns {NextResponse} Payment intent client secret and amount
+ */
 export async function POST(request: NextRequest) {
   try {
     const {