feat: Add tag parameter support to GTT orders

[Shiv-Expert2503]

Issue

Resolves: #207 - GTT orders missing tag parameter support

Problem

Placing regular orders supports the tag parameter, but the place_gtt() method in the Python client does not expose it. This forces users to maintain external mapping to trace GTT-triggered orders back to their strategies.

Solution

Extended place_gtt() and modify_gtt() methods to include an optional tag parameter and forward it to the API request.

Changes Made

Core Implementation (kiteconnect/connect.py)

• Modified _get_gtt_payload() to accept optional tag parameter
• Updated place_gtt() method signature to include tag=None
• Updated modify_gtt() method signature to include tag=None
• Added conditional logic to include tag in API payload when provided

Testing (tests/unit/test_connect.py)

• Added test_place_gtt_with_tag() test case
• Added test_modify_gtt_with_tag() test case
• All 46 existing tests continue to pass

Documentation (examples/gtt_order.py)

• Added tag parameter usage examples for both single and OCO GTT orders
• Included descriptive comments explaining functionality
• Note: Tag values ("my_strategy_1", "my_strategy_2") are example placeholders

Usage Examples

Single GTT with tag

kite.place_gtt(
    trigger_type=kite.GTT_TYPE_SINGLE,
    tradingsymbol="SBIN",
    exchange="NSE",
    trigger_values=[470],
    last_price=473,
    orders=orders,
    tag="my_trading_strategy"  # NEW: Optional tag parameter
)

kite.place_gtt(
    trigger_type=kite.GTT_TYPE_OCO,
    tradingsymbol="SBIN",
    exchange="NSE",
    trigger_values=[470, 480],
    last_price=473,
    orders=orders,
    tag="risk_management_strategy"  # NEW: Optional tag parameter
)

Backward Compatibility

• Zero breaking changes - All existing code continues to work
• Optional parameter - tag=None by default
• API consistency - Follows same pattern as regular place_order() method

Testing

• Added 2 new test cases for tag functionality
• All 46 unit tests pass
• New tag functionality thoroughly tested
• Manual testing completed with mock responses

Impact

• Users can now trace GTT orders to strategies without external mapping
• Improved order management and debugging capabilities
• Enhanced integration with trading strategy frameworks