refactor(settings): separate preview validation from internal failures

tests/test_settings_page.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from app.models.portfolio import PortfolioConfig
+from app.pages.settings import _save_card_status_text
+
+
+def test_save_card_status_text_for_clean_state() -> None:
+    config = PortfolioConfig(gold_value=215_000.0, entry_price=215.0, loan_amount=145_000.0)
+
+    text = _save_card_status_text(config)
+
+    assert text.startswith("Last saved:")
+    assert "Unsaved changes" not in text
+    assert "Unsaved invalid changes" not in text
+    assert "Save failed" not in text
+
+
+def test_save_card_status_text_for_dirty_state() -> None:
+    last_saved = PortfolioConfig(gold_value=215_000.0, entry_price=215.0, loan_amount=145_000.0)
+    preview = PortfolioConfig(gold_value=215_000.0, entry_price=215.0, loan_amount=150_000.0)
+
+    text = _save_card_status_text(last_saved, preview_config=preview)
+
+    assert text.startswith("Unsaved changes — Last saved:")
+
+
+def test_save_card_status_text_for_invalid_state() -> None:
+    config = PortfolioConfig(gold_value=215_000.0, entry_price=215.0, loan_amount=145_000.0)
+
+    text = _save_card_status_text(config, invalid=True)
+
+    assert text.startswith("Unsaved invalid changes — Last saved:")
+
+
+def test_save_card_status_text_for_save_failure() -> None:
+    config = PortfolioConfig(gold_value=215_000.0, entry_price=215.0, loan_amount=145_000.0)
+
+    text = _save_card_status_text(config, save_failed=True)
+
+    assert text.startswith("Save failed — Last saved:")