feat: add marketing tools registry for agent discovery

Create centralized tools/ directory with REGISTRY.md index and 29
integration guides covering analytics, SEO, CRM, payments, referral,
email, ads, automation, and commerce platforms.

Each guide includes API endpoints, authentication, common operations,
and links to relevant skills. Updated AGENTS.md and key skills
(referral-program, analytics-tracking, email-sequence, paid-ads)
with tool integration references.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tools/integrations/rewardful.md

@@ -0,0 +1,147 @@
+# Rewardful
+
+Affiliate and referral tracking for Stripe-based SaaS businesses.
+
+## Capabilities
+
+| Integration | Available | Notes |
+|-------------|-----------|-------|
+| API | ✓ | REST API for affiliates, referrals, commissions |
+| MCP | - | Not available |
+| CLI | - | Not available |
+| SDK | - | API-only, JavaScript snippet for tracking |
+
+## Authentication
+
+- **Type**: API Key
+- **Header**: `Authorization: Bearer {api_secret}`
+- **Get key**: Settings > API in Rewardful dashboard
+
+## Common Agent Operations
+
+### List affiliates
+
+```bash
+GET https://api.getrewardful.com/v1/affiliates
+```
+
+### Get affiliate by ID
+
+```bash
+GET https://api.getrewardful.com/v1/affiliates/{affiliate_id}
+```
+
+### Search affiliate by email
+
+```bash
+GET https://api.getrewardful.com/v1/affiliates?email=affiliate@example.com
+```
+
+### Get referral by Stripe customer
+
+```bash
+GET https://api.getrewardful.com/v1/referrals?stripe_customer_id={customer_id}
+```
+
+### List referrals for affiliate
+
+```bash
+GET https://api.getrewardful.com/v1/referrals?affiliate_id={affiliate_id}
+```
+
+### Get commission details
+
+```bash
+GET https://api.getrewardful.com/v1/commissions/{commission_id}
+```
+
+### List commissions
+
+```bash
+GET https://api.getrewardful.com/v1/commissions?affiliate_id={affiliate_id}
+```
+
+### Create affiliate link
+
+```bash
+POST https://api.getrewardful.com/v1/affiliates/{affiliate_id}/links
+
+{
+  "token": "custom-link-token",
+  "url": "https://example.com/pricing"
+}
+```
+
+### Update affiliate
+
+```bash
+PUT https://api.getrewardful.com/v1/affiliates/{affiliate_id}
+
+{
+  "first_name": "John",
+  "last_name": "Doe",
+  "paypal_email": "john@example.com"
+}
+```
+
+## JavaScript Tracking
+
+### Install snippet
+
+```html
+<script>
+(function(w,r){w._rwq=r;w[r]=w[r]||function(){(w[r].q=w[r].q||[]).push(arguments)}})(window,'rewardful');
+</script>
+<script async src='https://r.wdfl.co/rw.js' data-rewardful='YOUR_API_KEY'></script>
+```
+
+### Track conversion manually
+
+```javascript
+rewardful('convert', { email: 'customer@example.com' });
+```
+
+## Webhook Events
+
+| Event | When |
+|-------|------|
+| `affiliate.created` | New affiliate signs up |
+| `affiliate.approved` | Affiliate approved |
+| `referral.created` | New referral tracked |
+| `referral.converted` | Referral becomes customer |
+| `commission.created` | Commission generated |
+| `commission.paid` | Commission paid out |
+
+## Key Objects
+
+- **Affiliate** - Partner promoting your product
+- **Referral** - Tracked visit/lead from affiliate
+- **Commission** - Earned payment for affiliate
+- **Campaign** - Program with specific terms
+- **Link** - Tracking URL for affiliate
+
+## Integration with Stripe
+
+Rewardful automatically:
+1. Tracks referral cookie when user visits via affiliate link
+2. Associates Stripe customer with referral on checkout
+3. Creates commissions when subscriptions are paid
+4. Handles recurring commissions for subscriptions
+
+## When to Use
+
+- Setting up affiliate/referral programs for SaaS
+- Tracking referral attribution from Stripe payments
+- Managing affiliate relationships
+- Processing affiliate payouts
+- Analyzing referral program performance
+
+## Rate Limits
+
+- 120 requests per minute
+- Contact support for higher limits
+
+## Relevant Skills
+
+- referral-program
+- pricing-strategy