BUG-044: test_ci_quality_gate expects windows-postgres CI job that does not exist #13

Summary

17 tests in TestWindowsPostgresJob and TestQualityGateStructure fail
because quality-gate.yml only defines two jobs (free-tier and
integration-postgres). The windows-postgres job existed in the now-
archived PostgreDataMigrationApp but was never ported to this repo.

Additionally, TestGapAnalysisG2Closed (4 tests) expects GAP_ANALYSIS.md
to show G2 as closed, but it is still described as open.

Failing tests

• tests/test_ci_quality_gate.py::TestQualityGateStructure::test_has_windows_postgres_job
• tests/test_ci_quality_gate.py::TestWindowsPostgresJob (16 tests)
• tests/test_ci_quality_gate.py::TestGapAnalysisG2Closed (4 tests)

Fix (recommended — Option A)

Remove TestWindowsPostgresJob and test_has_windows_postgres_job from
tests/test_ci_quality_gate.py. The ubuntu integration-postgres job
already covers the full test suite. Update GAP_ANALYSIS.md to mark G2 as
accepted/deferred rather than open, and update TestGapAnalysisG2Closed
to match.

Fix (Option B — not recommended)

Port the Windows PostgreSQL CI job from the archived repo into quality-gate.yml.
Requires pg_ctl/initdb setup on a windows-latest runner, which is non-trivial
and duplicates coverage already provided by integration-postgres.

Files affected

• tests/test_ci_quality_gate.py
• GAP_ANALYSIS.md
• .github/workflows/quality-gate.yml (Option B only)