Remove LongBridge fractional execution config

[Pigbibi]

Summary

• remove LongBridge fractional quantity env config from runtime wiring
• execute LongBridge orders as whole shares only while keeping strategy allocation targets fractional-capable
• delete temporary HK simulated-account API probe workflow and tests
• sync Cloud Run env cleanup for stale fractional execution vars

Tests

• /home/ubuntu/Projects/LongBridgePlatform/.venv/bin/python -m unittest tests.test_runtime_config_support tests.test_runtime_composer tests.test_rebalance_service -v
• bash tests/test_sync_cloud_run_env_workflow.sh
• /home/ubuntu/Projects/LongBridgePlatform/.venv/bin/python -m ruff check application notifications runtime_config_support.py strategy_runtime.py main.py tests/test_runtime_config_support.py tests/test_runtime_composer.py tests/test_rebalance_service.py
• git diff --check