fix: address seat count review feedback

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: asizikov

src/App.tsx

@@ -284,16 +284,16 @@ function App() {
     setBudgetSimulation(null)
     setBudgetSimulationError(null)
     setIsApplyingBudgetSimulation(false)
+    if (!onError) {
+      setError(null)
+    }
 
     try {
       const nextData = await buildReportData(file, resolvedOverrides)
       if (runId !== latestRunIdRef.current) return false
 
       applyProcessedData(nextData)
       setSeatOverrides(compactSeatOverrides(resolvedOverrides))
-      if (!onError) {
-        setError(null)
-      }
       return true
     } catch (err) {
       if (runId !== latestRunIdRef.current) return false

src/utils/seatCounts.test.ts

@@ -4,14 +4,18 @@ import { getSeatReductionError, parseSeatCountInput } from './seatCounts'
 describe('seat count helpers', () => {
   it('normalizes seat count input to the historical minimum', () => {
     expect(parseSeatCountInput('', 10)).toBe(10)
+    expect(parseSeatCountInput('  ', 10)).toBe(10)
+    expect(parseSeatCountInput(' 12.9 ', 10)).toBe(12)
     expect(parseSeatCountInput('12.9', 10)).toBe(12)
     expect(parseSeatCountInput('not-a-number', 10)).toBe(10)
     expect(parseSeatCountInput('8', 10)).toBe(10)
   })
 
   it('reports only reductions below the historical count', () => {
     expect(getSeatReductionError('', 10)).toBeNull()
+    expect(getSeatReductionError('  ', 10)).toBeNull()
     expect(getSeatReductionError('10', 10)).toBeNull()
+    expect(getSeatReductionError(' 12 ', 10)).toBeNull()
     expect(getSeatReductionError('12', 10)).toBeNull()
     expect(getSeatReductionError('8', 10)).toBe('Cannot go below 10 because that count comes from historical report data.')
   })

src/utils/seatCounts.ts

@@ -14,9 +14,10 @@ export function parseSeatCountInput(raw: string, minimum: number): number {
 }
 
 export function getSeatReductionError(value: string, minimum: number): string | null {
-  if (value === '') return null
+  const trimmed = value.trim()
+  if (trimmed === '') return null
 
-  const parsed = Number(value)
+  const parsed = Number(trimmed)
   if (!Number.isFinite(parsed) || Math.floor(parsed) >= minimum) return null
 
   return `Cannot go below ${minimum.toLocaleString()} because that count comes from historical report data.`