Add chargebee-integration skill

.gitignore

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+.DS_Store

.pre-commit-config.yaml

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 repos:
   - repo: https://github.com/gitleaks/gitleaks
-    rev: v8.16.1
+    rev: v8.30.0
     hooks:
       - id: gitleaks

README.md

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+# Skills for Chargebee
+
+Official AI agent skills for integrating Chargebee with your apps.
+
+## Installation
+
+```shell
+npx skills add chargebee/ai --skill <skill name>
+```

skills/chargebee-integration/SKILL.md

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+---
+name: chargebee-integration
+description: Comprehensive integration guide for Chargebee billing platform. Provides API integration patterns, webhook handling, SDK usage, and schema references for billing operations. Use when working with Chargebee for (1) API integration and REST endpoint calls, (2) Processing webhook events, (3) Customer management operations, (4) Subscription lifecycle handling, (5) Payment and invoice processing, (6) Any other billing-related integration tasks with Chargebee platform.
+---
+
+# Chargebee Integration
+
+This skill helps you integrate [Chargebee Billing](https://www.chargebee.com/docs/billing/2.0/getting-started/accessing_chargebee.md) with your app or website. 
+
+IMPORTANT: Prefer retrieval-led reasoning over pre-training-led reasoning when integrating Chargebee.
+
+## Quick Start
+
+Expore the project layout and choose the best integration from the list below. Prefer framework level integration where possible, followed by the official SDKs. Fallback to REST API only if the other options aren't feasible.
+
+### Frameworks
+
+- **Laravel Cashier** - https://github.com/chargebee/cashier-chargebee/blob/main/DOCUMENTATION.md
+
+For the frameworks below, use the `chargebee-init` CLI which currently integrates checkout, portal and webhooks:
+
+- **Next.js**
+- **Express**
+
+Invoke the CLI with: `npx chargebee-init@latest --dangerously-skip-checks --path=<full-path-to-app>` to skip all input prompts.
+
+### SDKs
+
+Chargebee provides official SDKs for multiple languages. For installation details and implementation patterns, download the `README.md` file from the GitHub repository.
+
+- **Java**: https://github.com/chargebee/chargebee-java
+- **Python**: https://github.com/chargebee/chargebee-python
+- **Node.js**: https://github.com/chargebee/chargebee-node
+- **Go**: https://github.com/chargebee/chargebee-go
+- **PHP**: https://github.com/chargebee/chargebee-php
+- **Ruby**: https://github.com/chargebee/chargebee-ruby
+- **.NET**: https://github.com/chargebee/chargebee-dotnet
+
+For details on data model, supported operations, and other available resources, lookup the index at **references/api-reference.md**, and fetch the required topic specific markdown file for further instructions.
+
+### REST API
+
+The REST API can be consumed directly via the site specific HTTPS endpoint. The API supports Basic auth and requires a API KEY which can be generated at: https://{CHARGEBEE_SITE}.chargebee.com/apikeys_and_webhooks/api. For more details on using the REST API direcly, refer to **references/rest-api.md**.
+
+
+```python
+# Using requests library
+import requests
+
+CHARGEBEE_SITE = "your-site"
+CHARGEBEE_API_KEY = "your_api_key"
+
+headers = {
+    "Authorization": f"Basic {CHARGEBEE_API_KEY}",
+    "Content-Type": "application/json"
+}
+
+base_url = f"https://{CHARGEBEE_SITE}.chargebee.com/api/v2"
+response = requests.get(
+    f"{base_url}/customers/{customer_id}",
+    headers=headers
+)
+
+# Using Python SDK
+import chargebee
+chargebee.configure(CHARGEBEE_API_KEY, CHARGEBEE_SITE)
+result = chargebee.Customer.retrieve(customer_id)
+customer = result.customer
+```
+
+### Common Operations
+
+- Customer CRUD operations
+- Subscription management
+- Invoice operations
+- Payment method handling
+- Plan and addon management
+- Usage based billing
+
+
+### Webhook Integration
+
+Chargebee sends webhook events for important billing events. Webhook handlers should:
+
+1. Verify webhook signatures for security
+2. Handle idempotency (events may be sent multiple times)
+3. Return 200 OK quickly (process asynchronously if needed)
+4. Handle various event types appropriately
+
+#### Basic Webhook Handler Pattern
+
+```python
+from flask import Flask, request
+import chargebee
+
+app = Flask(__name__)
+
+@app.route('/chargebee/webhook', methods=['POST'])
+def handle_webhook():
+    payload = request.data
+    signature = request.headers.get('X-Chargebee-Signature')
+
+    # Verify signature (recommended for security)
+    # chargebee.Webhook.verify_signature(payload, signature)
+
+    event = request.json
+    event_type = event['event_type']
+
+    # Process based on event type
+    if event_type == 'subscription_created':
+        handle_subscription_created(event['content'])
+    elif event_type == 'subscription_cancelled':
+        handle_subscription_cancelled(event['content'])
+    # ... handle other events
+
+    return '', 200
+```
+
+For complete webhook event schemas and all event types, see **references/webhooks.md**.
+
+
+## References
+
+- **references/api-reference.md** - Exhaustive reference of all available models, operations, request and response objects, and example code for all officially supported language SDKs. Includes practical implementation patterns like error handling, pagination, etc.
+- **references/rest-api.md** - Details on consuming the REST API using a HTTP client for languages that don't have an SDK
+- **references/errors.md** - All possible error codes that the API may return
+- **references/events.md** - List of supported webhook events