Cal drift: extend framework to Passive Calibration runs

[RFingAdam]

Background

v1 of calibration drift tracking (see plot_antenna/cal_drift.py) records Active Chamber Calibration runs only — the TRP Cal files produced by generate_active_cal_file(). Passive calibration uses a different file schema.

User has a 2026-4-14 Passive Calibration folder in ~/Downloads/Calibration Data/ but is unsure how complete historical passive-cal data is across 2021/2023/2024.

Goal

Extend the drift tracker to also handle passive-cal runs so chamber drift on the passive side is tracked with the same workflow.

Acceptance Criteria

• plot_antenna/cal_drift.py adds a passive-cal parser (new parse_passive_cal_file() or equivalent).
• CalRunMeta gains a cal_type field ("active" | "passive"); existing active-cal rows default to "active" on migration.
• Tools → Calibration Drift History… dialog left panel filters or tabs by cal_type so active and passive show separately.
• import_historical_dir() picks up both active (TRP Cal *.txt) and passive cal files.
• MCP cal_drift_list_runs / cal_drift_compare accept an optional cal_type filter.
• Tests: new fixtures in tests/fixtures/cal_drift/ for passive; parity tests for parse + record + compare.
• Ingesting ~/Downloads/Calibration Data/2026-4-14 Passive Calibration/ completes with 0 failures.

Notes

• Passive cal files likely have different column layout — confirm schema by inspecting a 2026-04-14 passive sample before writing the parser.
• The method-consistency table should add passive-specific fields (reference antenna model, cable loss, etc.) if those differ from active.

Related: v1 tracker lives at plot_antenna/cal_drift.py + plot_antenna/gui/cal_drift_dialog.py + rflect-mcp/tools/cal_drift_tools.py.