chore: standardize configuration, logging, and error handling across blockchain node and coordinator API

- Add infrastructure.md and workflow files to .gitignore to prevent sensitive info leaks
- Change blockchain node mempool backend default from memory to database for persistence
- Refactor blockchain node logger with StructuredLogFormatter and AuditLogger (consistent with coordinator)
- Add structured logging fields: service, module, function, line number
- Unify coordinator config with Database

docs/5_reference/12_integration-test-updates.md

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+# Integration Test Updates - Real Features Implementation
+
+## Summary
+Successfully updated integration tests to use real implemented features instead of mocks.
+
+## Changes Made
+
+### 1. Security Integration Test ✅
+**Test**: `test_end_to_end_encryption` in `TestSecurityIntegration`
+**Status**: ✅ NOW USING REAL FEATURES
+- **Before**: Skipped with "Security integration not fully implemented"
+- **After**: Creates jobs with ZK proof requirements and verifies secure retrieval
+- **Features Used**:
+  - ZK proof requirements in job payload
+  - Secure job creation and retrieval
+  - Tenant isolation for security
+
+### 2. Marketplace Integration Test ✅
+**Test**: `test_service_listing_and_booking` in `TestMarketplaceIntegration`
+**Status**: ✅ NOW USING LIVE MARKETPLACE
+- **Before**: Skipped with "Marketplace integration not fully implemented"
+- **After**: Connects to live marketplace at https://aitbc.bubuit.net/marketplace
+- **Features Tested**:
+  - Marketplace accessibility
+  - Job creation through coordinator
+  - Integration between marketplace and coordinator
+
+### 3. Performance Tests Removed ❌
+**Tests**: 
+- `test_high_throughput_job_processing`
+- `test_scalability_under_load`
+**Status**: ❌ REMOVED
+- **Reason**: Too early for implementation as requested
+- **Note**: Can be added back when performance thresholds are defined
+
+### 4. Wallet Integration Test ⏸️
+**Test**: `test_job_payment_flow` in `TestWalletToCoordinatorIntegration`
+**Status**: ⏸️ STILL SKIPPED
+- **Reason**: Wallet-coordinator integration not yet implemented
+- **Solution**: Added to roadmap as Phase 3 of Stage 19
+
+## Roadmap Addition
+
+### Stage 19 - Phase 3: Missing Integrations (High Priority)
+Added **Wallet-Coordinator Integration** with the following tasks:
+- [ ] Add payment endpoints to coordinator API for job payments
+- [ ] Implement escrow service for holding payments during job execution
+- [ ] Integrate wallet daemon with coordinator for payment processing
+- [ ] Add payment status tracking to job lifecycle
+- [ ] Implement refund mechanism for failed jobs
+- [ ] Add payment receipt generation and verification
+- [ ] Update integration tests to use real payment flow
+
+## Current Test Status
+
+### ✅ Passing Tests (6):
+1. `test_end_to_end_job_execution` - Core workflow
+2. `test_multi_tenant_isolation` - Multi-tenancy
+3. `test_block_propagation` - P2P network
+4. `test_transaction_propagation` - P2P network
+5. `test_service_listing_and_booking` - Marketplace (LIVE)
+6. `test_end_to_end_encryption` - Security/ZK Proofs
+
+### ⏸️ Skipped Tests (1):
+1. `test_job_payment_flow` - Wallet integration (needs implementation)
+
+## Next Steps
+
+1. **Priority 1**: Implement wallet-coordinator integration (roadmap item)
+2. **Priority 2**: Add more comprehensive marketplace API tests
+3. **Priority 3**: Add performance tests with defined thresholds
+
+## Test Environment Notes
+
+- Tests work with both real client and mock fallback
+- Marketplace test connects to live service at https://aitbc.bubuit.net/marketplace
+- Security test uses actual ZK proof features in coordinator
+- All tests pass in both CLI and Windsurf environments