fix(merge): resolve post-merge type errors from batch-1 agents

- ScenarioPlanner.Baseline.shortCode: string → string | null (matches Prisma)
- ScenarioPlanner.SimulationResult.chargeabilityTarget: number → number | null
- Remove runtime Zod parse from scenario procedures (typed by Prisma already)
- Float64Array index access: add non-null assertions for noUncheckedIndexedAccess

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/projects/ScenarioPlanner.tsx

@@ -43,7 +43,7 @@ interface Baseline {
   project: {
     id: string;
     name: string;
-    shortCode: string;
+    shortCode: string | null;
     startDate: Date | string;
     endDate: Date | string;
     budgetCents: number | null;
@@ -600,7 +600,7 @@ interface SimulationResult {
   resourceImpacts: Array<{
     resourceId: string;
     resourceName: string;
-    chargeabilityTarget: number;
+    chargeabilityTarget: number | null;
     currentUtilization: number;
     scenarioUtilization: number;
     utilizationDelta: number;