[codex] Add LongBridge HK dry-run switch plan

[Pigbibi]

Summary

• extend the strategy switch plan with HK verify-only / dry-run options and explicit HK/.HK/HKD/XHKG env output
• add dry-run checklist fields for HK permissions, market-history feed, order preview, integer-share and lot-size checks
• make helper scripts ignore stale local sibling dependency checkouts that do not contain the required current modules
• document the HK verify-only command in README and docs/hk_equity_runtime.md

Validation

• /tmp/qsl-longbridge-ci-venv/bin/python -m pytest -q tests/test_runtime_config_support.py — 43 passed, 12 subtests passed
• /tmp/qsl-longbridge-ci-venv/bin/python -m pytest -q tests — 150 passed, 12 subtests passed
• /tmp/qsl-longbridge-ci-venv/bin/python -m compileall -q scripts tests runtime_config_support.py strategy_registry.py
• git diff --check

Production impact

• No Cloud Run deployment or live trading config changes.
• The generated HK plan sets LONGBRIDGE_DRY_RUN_ONLY=true when --dry-run-only is used and is only printed, not applied.