Build GitHub Action: NEAR Testnet Deploy

Description

## Overview
Create a GitHub Action specifically for deploying to NEAR testnet with automatic faucet funding and test execution.

## Why This Matters
Testnet deployment should be effortless. This action handles the complete testnet workflow.

## Technical Requirements
- Auto-create testnet account if needed
- Request faucet funding
- Deploy contract
- Run basic smoke tests
- Report results

## Deliverables
1. GitHub Action on Marketplace
2. Automatic testnet setup
3. Test execution
4. Clear status reporting