docs: update documentation links and expand Q2-Q3 2026 milestone plan

- Fix broken documentation links in intro.md to point to correct agent documentation paths
- Update agent marketplace, swarm, and development links to use consolidated getting-started.md
- Expand Q2-Q3 2026 milestone plan from "OpenClaw Agent Economic Model & Scalability" to "Global Marketplace Expansion"
- Add comprehensive global infrastructure scaling strategy with multi-region deployment
- Include cross-chain agent economics

docs/8_development/7_payments-receipts.md

@@ -108,7 +108,7 @@ curl https://aitbc.bubuit.net/api/v1/receipts?client=<your_address>
 3. Send Bitcoin to your deposit address
 4. Receive AITBC at current exchange rate (1 BTC = 100,000 AITBC)
 
-See [Bitcoin Wallet Setup](BITCOIN-WALLET-SETUP.md) for detailed instructions.
+See [Bitcoin Wallet Setup](../6_architecture/6_trade-exchange.md) for detailed instructions.
 
 ### Via Mining
 
@@ -152,5 +152,5 @@ If you believe a payment was incorrect:
 
 ## Next Steps
 
-- [Troubleshooting](troubleshooting.md) - Common payment issues
-- [Getting Started](getting-started.md) - Back to basics
+- [Troubleshooting](../0_getting_started/2_installation.md) - Common payment issues
+- [Getting Started](../0_getting_started/1_intro.md) - Back to basics