Feature/delta team/epic r04 (#7)

## Summary

epic r04 - begin refactor

## Change Type

- [x] Cowork feature
- [ ] Bug fix
- [ ] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

---------

Co-authored-by: Anh Tran Nguyen Minh <anhtnm1@fpt.com>
Co-authored-by: Huong Le Thi Thien <huongltt35@fpt.com>
Co-authored-by: Nam Pham Dinh Thanh <nampdt@fpt.com>
Co-authored-by: Vu Dam Tuan <vudt15@fpt.com>
Co-authored-by: Hiep Ha Van <hiephv3@fpt.com>
Co-authored-by: Lam Hoang Van <lamhv7@fpt.com>
Reviewed-on: #7
Co-authored-by: Duy Le Huu <duylh19@fpt.com>

tests/test_monitoring_pricing_panel.py

@@ -0,0 +1,49 @@
+"""Task 1 (sub-step 6f, follow-up) — PricingPanel, split out of overview_tab.py
+to keep that file under the 400-line quality rule."""
+from __future__ import annotations
+
+import copy
+import os
+
+os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
+
+import pytest
+
+QApplication = pytest.importorskip("PySide6.QtWidgets").QApplication
+
+from cowork_local.config import AppConfig, DEFAULT_CONFIG
+from cowork_local.presentation.monitoring.tabs.pricing_panel import PricingPanel
+
+
+@pytest.fixture(scope="module")
+def qapp():
+    app = QApplication.instance() or QApplication([])
+    yield app
+
+
+class _FakeCtx:
+    def __init__(self, tmp_path):
+        self.config = AppConfig(data=copy.deepcopy(DEFAULT_CONFIG), path=tmp_path / "c.json")
+
+    def save(self):
+        pass
+
+
+def test_construction_and_retranslate(qapp, tmp_path) -> None:
+    panel = PricingPanel(_FakeCtx(tmp_path), on_status_message=lambda _m: None)
+    panel.retranslate()
+
+
+def test_add_and_delete_pricing_row_round_trip(qapp, tmp_path, monkeypatch) -> None:
+    from PySide6.QtWidgets import QInputDialog
+
+    ctx = _FakeCtx(tmp_path)
+    panel = PricingPanel(ctx, on_status_message=lambda _m: None)
+    monkeypatch.setattr(QInputDialog, "getText", staticmethod(lambda *a, **k: ("gpt-test", True)))
+    panel._add_pricing_row()
+    assert panel.table.rowCount() == 1
+    assert panel.table.item(0, 0).text() == "gpt-test"
+
+    panel.table.selectRow(0)
+    panel._delete_pricing_row()
+    assert panel.table.rowCount() == 0