feat: Add blue-green deployment strategy support for zero downtime

[vishale6x]

• Implement automatic blue-green strategy detection on connection
• Add strategy header to all gRPC requests
• Handle graceful strategy transitions without query interruption
• Support 456 error handling for strategy mismatches
• Add thread-safe and process-safe strategy caching
• Update all API responses to include optional new_strategy field
• Add comprehensive testing with mock gRPC server
• Update documentation for blue-green deployment

Key features:

• Zero downtime during server deployments
• Automatic failover between blue/green strategies
• Per-query strategy tracking for consistency
• 5-minute strategy cache for performance
• Compatible with multi-threaded/multi-process applications

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR implements blue-green deployment strategy support for the e6data Python connector to enable zero downtime deployments. The implementation includes automatic strategy detection, graceful transitions, and comprehensive error handling to ensure query continuity during server deployments.

Key changes:

• Added automatic blue-green strategy detection and header injection for all gRPC requests
• Implemented 456 error handling for strategy mismatches with automatic failover
• Added thread-safe and process-safe strategy caching with 5-minute TTL

Reviewed Changes

Copilot reviewed 67 out of 69 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
test/verify_decimal_fix.py	Test validation for DECIMAL128 binary data handling edge cases
test/validate_implementation.py	Comprehensive validation suite for DECIMAL128 IEEE 754-2008 implementation
test/validate_decimal128.py	Integration test for DECIMAL128 parsing with VectorType support
test/test_user_binary_value.py	Specific test for problematic DECIMAL128 binary patterns
test/test_strategy_sharing_fix.py	Validation of strategy state sharing between ClusterManager and e6data_grpc
test/test_strategy_persistence_fix.py	Test for strategy persistence after cluster resume operations
test/test_strategy_logic.py	Mock server testing for strategy logic and transitions
test/test_strategy.py	Comprehensive strategy detection tests with multi-threading/processing
test/test_specific_binary.py	Analysis of specific DECIMAL128 binary encoding patterns
test/test_multiprocessing_fix.py	Verification of multiprocessing RuntimeError fixes
test/test_mock_server.py	Client testing against mock gRPC server for strategy switching
test/test_manual_analysis.py	Manual analysis tools for 38-digit DECIMAL128 values
test/test_known_case.py	Validation of known working DECIMAL128 test cases
test/test_improved_parsing.py	Enhanced DECIMAL128 binary parsing with IEEE 754-2008 support
test/test_fix.py	Basic DECIMAL128 invalid binary data handling test
test/test_decimal128_parsing.py	Core DECIMAL128 parsing functionality tests
test/test_decimal128_binary_parsing.py	Binary format parsing tests for IEEE 754-2008 Decimal128
test/test_current_implementation.py	Testing current DECIMAL128 implementation with field extraction
test/test_comprehensive.py	Full test suite covering all DECIMAL128 expected values
test/test_cluster_manager_strategy.py	ClusterManager integration with strategy support
test/test_cluster_manager_none_strategy.py	Testing ClusterManager behavior with no active strategy
test/test_cluster_manager_efficiency.py	Efficiency testing for established strategy reuse
test/test_all_decimal128_cases.py	Coverage of all DECIMAL128 cases from query output
test/test_38_nines.py	Specific test for 38-digit number (99999...9999) parsing
setup.py	Version bump to 2.2.6
run_mock_test.sh	Shell script for running mock server and test client

Comments suppressed due to low confidence (1)

test/test_comprehensive.py:45

• [nitpick] The test case description says 'Row 5: 0' but the expected value should be more descriptive in the test data structure. Consider using 'expected_value' or similar for clarity.

            'expected': 0