docs: Ledger Live integration, contract deploy learnings, NEXT_STEPS updates

- ADD_CHAIN138_TO_LEDGER_LIVE: Ledger form done; public code review repo bis-innovations/LedgerLive; init/push commands
- CONTRACT_DEPLOYMENT_RUNBOOK: Chain 138 gas price 1 gwei, 36-addr check, TransactionMirror workaround
- CONTRACT_*: AddressMapper, MirrorManager deployed 2026-02-12; 36-address on-chain check
- NEXT_STEPS_FOR_YOU: Ledger done; steps completable now (no LAN); run-completable-tasks-from-anywhere
- MASTER_INDEX, OPERATOR_OPTIONAL, SMART_CONTRACTS_INVENTORY_SIMPLE: updates
- LEDGER_BLOCKCHAIN_INTEGRATION_COMPLETE: bis-innovations/LedgerLive reference

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/11-references/API_DOCUMENTATION.md

@@ -1,6 +1,27 @@
-# Bridge API Documentation
+# API Documentation Index
 
-**Purpose**: API documentation for bridge operations
+**Last Updated:** 2026-01-31  
+**Document Version:** 1.0  
+**Status:** Active Documentation
+
+---
+
+**Purpose**: Master index for API documentation across the project
+
+---
+
+## API References
+
+| API | Document | Description |
+|-----|----------|-------------|
+| **Bridge API** | This file | Bridge operations, CCIP, contract addresses |
+| **DBIS Core API** | [DBIS_CORE_API_REFERENCE.md](DBIS_CORE_API_REFERENCE.md) | DBIS Core APIs including Crypto.com OTC 2.0 |
+
+---
+
+## Bridge API Documentation
+
+### Bridge Operations
 
 ---