feat(CORE-001D): close remaining boundary cleanup slices

app/services/event_comparison_ui.py

@@ -6,6 +6,7 @@ from datetime import date
 from app.models.backtest import BacktestScenario, EventComparisonReport
 from app.services.backtesting.comparison import EventComparisonService
 from app.services.backtesting.historical_provider import DailyClosePoint, SyntheticHistoricalProvider
+from app.services.backtesting.input_normalization import normalize_historical_scenario_inputs
 from app.services.event_presets import EventPresetService
 from app.services.strategy_templates import StrategyTemplateService
 
@@ -151,12 +152,12 @@ class EventComparisonPageService:
             raise ValueError("Preset selection is required")
         if not template_slugs:
             raise ValueError("Select at least one strategy template.")
-        if underlying_units <= 0:
-            raise ValueError("Underlying units must be positive")
-        if loan_amount < 0:
-            raise ValueError("Loan amount must be non-negative")
-        if not 0 < margin_call_ltv < 1:
-            raise ValueError("Margin call LTV must be between 0 and 1")
+
+        normalized_inputs = normalize_historical_scenario_inputs(
+            underlying_units=underlying_units,
+            loan_amount=loan_amount,
+            margin_call_ltv=margin_call_ltv,
+        )
 
         preset = self.event_preset_service.get_preset(preset_slug)
         normalized_symbol = preset.symbol.strip().upper()
@@ -179,15 +180,23 @@ class EventComparisonPageService:
                     preset.window_end,
                 )
                 if preview_history:
-                    _validate_initial_collateral(underlying_units, preview_history[0].close, loan_amount)
+                    _validate_initial_collateral(
+                        normalized_inputs.underlying_units,
+                        preview_history[0].close,
+                        normalized_inputs.loan_amount,
+                    )
             raise
-        _validate_initial_collateral(underlying_units, preview.initial_portfolio.entry_spot, loan_amount)
+        _validate_initial_collateral(
+            normalized_inputs.underlying_units,
+            preview.initial_portfolio.entry_spot,
+            normalized_inputs.loan_amount,
+        )
         return self.comparison_service.compare_event_from_inputs(
             preset_slug=preset.slug,
             template_slugs=template_slugs,
-            underlying_units=underlying_units,
-            loan_amount=loan_amount,
-            margin_call_ltv=margin_call_ltv,
+            underlying_units=normalized_inputs.underlying_units,
+            loan_amount=normalized_inputs.loan_amount,
+            margin_call_ltv=normalized_inputs.margin_call_ltv,
         )
 
     @staticmethod