Move live/network tests out of CI into pre-push git hook

[sevakram]

Problem

test_bse_live.py and other tests making real network API calls (BSE/NSE) are slow and fail in CI (blocked/rate-limited API responses).

Solution

• Tagged network-dependent tests with @pytest.mark.live
• CI runs pytest -m "not live" to skip live tests
• New .githooks/pre-push hook runs all tests (including live) on every push — this is the gating check that catches upstream API changes
• Fixed test_bhavcopy_recent to use a fixed past date (was using date.today() which fails when market hasn't started)
• Default pytest still runs everything; CI and hook explicitly opt in/out of live tests

Usage

To enable the hook for your checkout:

git config core.hooksPath .githooks

Skip checks on push: git push --no-verify