fix(UX-001): address layout review findings

app/pages/backtests.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import logging
 from datetime import date, datetime
 
 from fastapi.responses import RedirectResponse
@@ -10,6 +11,8 @@ from app.models.workspace import get_workspace_repository
 from app.pages.common import dashboard_page, split_page_panes
 from app.services.backtesting.ui_service import BacktestPageRunResult, BacktestPageService
 
+logger = logging.getLogger(__name__)
+
 
 def _chart_options(result: BacktestPageRunResult) -> dict:
     template_result = result.run_result.template_results[0]
@@ -133,18 +136,23 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
             except ValueError as exc:
                 raise ValueError(f"{field_name} must be in YYYY-MM-DD format") from exc
 
-        def render_seeded_summary(*, entry_spot: float | None = None) -> None:
+        def derive_entry_spot() -> tuple[float | None, str | None]:
+            try:
+                resolved_entry_spot = service.derive_entry_spot(
+                    str(symbol_input.value or "GLD"),
+                    parse_iso_date(start_input.value, "Start date"),
+                    parse_iso_date(end_input.value, "End date"),
+                )
+            except (ValueError, KeyError) as exc:
+                return None, str(exc)
+            return resolved_entry_spot, None
+
+        def render_seeded_summary(*, entry_spot: float | None = None, entry_spot_error: str | None = None) -> None:
             seeded_summary.clear()
             resolved_entry_spot = entry_spot
-            if resolved_entry_spot is None:
-                try:
-                    resolved_entry_spot = service.derive_entry_spot(
-                        str(symbol_input.value or "GLD"),
-                        parse_iso_date(start_input.value, "Start date"),
-                        parse_iso_date(end_input.value, "End date"),
-                    )
-                except (ValueError, KeyError):
-                    resolved_entry_spot = None
+            resolved_error = entry_spot_error
+            if resolved_entry_spot is None and resolved_error is None:
+                resolved_entry_spot, resolved_error = derive_entry_spot()
             with seeded_summary:
                 ui.label("Scenario Summary").classes("text-lg font-semibold text-slate-900 dark:text-slate-100")
                 with ui.grid(columns=1).classes("w-full gap-4 sm:grid-cols-2 lg:grid-cols-1 xl:grid-cols-2"):
@@ -159,7 +167,7 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
                         ),
                         (
                             "Entry spot",
-                            f"${resolved_entry_spot:,.2f}" if resolved_entry_spot is not None else "Pending",
+                            f"${resolved_entry_spot:,.2f}" if resolved_entry_spot is not None else "Unavailable",
                         ),
                     ]
                     for label, value in cards:
@@ -168,15 +176,34 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
                         ):
                             ui.label(label).classes("text-sm text-slate-500 dark:text-slate-400")
                             ui.label(value).classes("text-xl font-bold text-slate-900 dark:text-slate-100")
+                if resolved_error:
+                    ui.label(resolved_error).classes("text-sm text-amber-700 dark:text-amber-300")
 
-        def render_result_validation(message: str) -> None:
+        def render_result_state(title: str, message: str, *, tone: str = "info") -> None:
+            tone_classes = {
+                "info": "border-sky-200 bg-sky-50 dark:border-sky-900/60 dark:bg-sky-950/30",
+                "warning": "border-amber-200 bg-amber-50 dark:border-amber-900/60 dark:bg-amber-950/30",
+                "error": "border-rose-200 bg-rose-50 dark:border-rose-900/60 dark:bg-rose-950/30",
+            }
+            text_classes = {
+                "info": "text-sky-800 dark:text-sky-200",
+                "warning": "text-amber-800 dark:text-amber-200",
+                "error": "text-rose-800 dark:text-rose-200",
+            }
             result_panel.clear()
             with result_panel:
                 with ui.card().classes(
-                    "w-full rounded-2xl border border-amber-200 bg-amber-50 shadow-sm dark:border-amber-900/60 dark:bg-amber-950/30"
+                    f"w-full rounded-2xl border shadow-sm {tone_classes.get(tone, tone_classes['info'])}"
                 ):
-                    ui.label("Scenario Results").classes("text-lg font-semibold text-slate-900 dark:text-slate-100")
-                    ui.label(message).classes("text-sm text-amber-800 dark:text-amber-200")
+                    ui.label(title).classes("text-lg font-semibold text-slate-900 dark:text-slate-100")
+                    ui.label(message).classes(f"text-sm {text_classes.get(tone, text_classes['info'])}")
+
+        def mark_results_stale() -> None:
+            render_result_state(
+                "Results out of date",
+                "Inputs changed. Run backtest again to refresh charts and daily results for the current scenario.",
+                tone="info",
+            )
 
         def render_result(result: BacktestPageRunResult) -> None:
             result_panel.clear()
@@ -263,20 +290,23 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
                     ).classes("w-full")
 
         def refresh_workspace_seeded_units() -> None:
-            if not workspace_id or config is None or config.gold_value is None:
-                return
-            try:
-                entry_spot = service.derive_entry_spot(
-                    str(symbol_input.value or "GLD"),
-                    parse_iso_date(start_input.value, "Start date"),
-                    parse_iso_date(end_input.value, "End date"),
-                )
-            except (ValueError, KeyError):
-                render_seeded_summary(entry_spot=None)
-                return
-            units_input.value = asset_quantity_from_workspace_config(config, entry_spot=entry_spot, symbol="GLD")
-            entry_spot_hint.set_text(f"Auto-derived entry spot: ${entry_spot:,.2f}")
-            render_seeded_summary(entry_spot=entry_spot)
+            entry_spot, entry_error = derive_entry_spot()
+            if (
+                workspace_id
+                and config is not None
+                and config.gold_value is not None
+                and entry_spot is not None
+            ):
+                units_input.value = asset_quantity_from_workspace_config(config, entry_spot=entry_spot, symbol="GLD")
+                entry_spot_hint.set_text(f"Auto-derived entry spot: ${entry_spot:,.2f}")
+            else:
+                entry_spot_hint.set_text("Entry spot unavailable until the scenario dates are valid.")
+            render_seeded_summary(entry_spot=entry_spot, entry_spot_error=entry_error)
+            mark_results_stale()
+
+        def on_form_change() -> None:
+            render_seeded_summary()
+            mark_results_stale()
 
         def run_backtest() -> None:
             validation_label.set_text("")
@@ -291,25 +321,39 @@ def _render_backtests_page(workspace_id: str | None = None) -> None:
                     margin_call_ltv=float(ltv_input.value or 0.0),
                 )
             except (ValueError, KeyError) as exc:
-                render_seeded_summary(entry_spot=None)
+                render_seeded_summary(entry_spot=None, entry_spot_error=None)
                 validation_label.set_text(str(exc))
-                render_result_validation(str(exc))
+                render_result_state("Scenario validation failed", str(exc), tone="warning")
                 return
             except Exception:
-                render_seeded_summary(entry_spot=None)
+                render_seeded_summary(entry_spot=None, entry_spot_error=None)
                 message = "Backtest failed. Please verify the scenario inputs and try again."
+                logger.exception(
+                    "Backtest page run failed for workspace=%s symbol=%s start=%s end=%s template=%s units=%s loan=%s margin_call_ltv=%s",
+                    workspace_id,
+                    symbol_input.value,
+                    start_input.value,
+                    end_input.value,
+                    template_select.value,
+                    units_input.value,
+                    loan_input.value,
+                    ltv_input.value,
+                )
                 validation_label.set_text(message)
-                render_result_validation(message)
+                render_result_state("Backtest failed", message, tone="error")
                 return
             render_result(result)
 
         if workspace_id:
             start_input.on_value_change(lambda _event: refresh_workspace_seeded_units())
             end_input.on_value_change(lambda _event: refresh_workspace_seeded_units())
-        template_select.on_value_change(lambda _event: render_seeded_summary())
-        units_input.on_value_change(lambda _event: render_seeded_summary())
-        loan_input.on_value_change(lambda _event: render_seeded_summary())
-        ltv_input.on_value_change(lambda _event: render_seeded_summary())
+        else:
+            start_input.on_value_change(lambda _event: on_form_change())
+            end_input.on_value_change(lambda _event: on_form_change())
+        template_select.on_value_change(lambda _event: on_form_change())
+        units_input.on_value_change(lambda _event: on_form_change())
+        loan_input.on_value_change(lambda _event: on_form_change())
+        ltv_input.on_value_change(lambda _event: on_form_change())
         run_button.on_click(lambda: run_backtest())
         render_seeded_summary(entry_spot=default_entry_spot)
         run_backtest()