fix(settings): preserve whole-dollar loan formatting

app/pages/settings.py

@@ -60,6 +60,15 @@ def settings_page(workspace_id: str) -> None:
             return None
         return parsed if parsed >= 0 else None
 
+    def display_number_input_value(value: object) -> str:
+        try:
+            parsed = float(value)
+        except (TypeError, ValueError):
+            return ""
+        if parsed.is_integer():
+            return str(int(parsed))
+        return str(parsed)
+
     def build_preview_config() -> PortfolioConfig:
         parsed_loan_amount = as_non_negative_float(loan_amount.value)
         if parsed_loan_amount is None:
@@ -132,7 +141,7 @@ def settings_page(workspace_id: str) -> None:
                 loan_amount = (
                     ui.input(
                         "Loan amount ($)",
-                        value=str(config.loan_amount),
+                        value=display_number_input_value(config.loan_amount),
                     )
                     .props("type=number min=0 step=1000")
                     .classes("w-full")
@@ -345,9 +354,12 @@ def settings_page(workspace_id: str) -> None:
 
             if collateral_value is not None and collateral_value > 0 and loan is not None:
                 ltv = (loan / collateral_value) * 100
-                buffer = ((margin or 0.0) - loan / collateral_value) * 100 if margin is not None else 0.0
                 ltv_display.set_text(f"{ltv:.1f}%")
+                if margin is not None:
+                    buffer = (margin - loan / collateral_value) * 100
                     buffer_display.set_text(f"{buffer:.1f}%")
+                else:
+                    buffer_display.set_text("—")
             else:
                 ltv_display.set_text("—")
                 buffer_display.set_text("—")

tests/test_settings_validation_playwright.py

@@ -36,4 +36,7 @@ def test_settings_reject_invalid_loan_amount_without_silent_zero_fallback() -> N
         assert "Server error" not in settings_text
         assert "Traceback" not in settings_text
 
+        page.reload(wait_until="domcontentloaded", timeout=30000)
+        expect(page.get_by_label("Loan amount ($)")).to_have_value("145000")
+
         browser.close()