refactor(wizard): enhance page range with extra validation in book creation

- Introduced a new utility function to parse and validate positive integers for start and end page inputs, ensuring they are within a valid range.
- Updated the configuration building logic to incorporate this validation, improving the robustness of the book creation process.

Author: Eliezir

apps/studio/src/components/wizard/bookCreationConfig.ts

@@ -1,9 +1,16 @@
 import type { WizardFormValues } from "./wizardForm"
 import { PRESETS } from "./constants"
 
+function parsePositiveInt(raw: string): number | undefined {
+  const n = Number(raw.trim())
+  return raw.trim() && Number.isInteger(n) && n >= 1 ? n : undefined
+}
+
 export function buildConfigOverrides(values: WizardFormValues): Record<string, unknown> {
-  const parsedStartPage = values.startPage.trim() ? Number(values.startPage) : undefined
-  const parsedEndPage = values.endPage.trim() ? Number(values.endPage) : undefined
+  const parsedStartPage = parsePositiveInt(values.startPage)
+  const parsedEndPage = parsePositiveInt(values.endPage)
+  const validPageRange =
+    parsedStartPage === undefined || parsedEndPage === undefined || parsedStartPage <= parsedEndPage
 
   const preset = PRESETS.find((p) => p.id === values.selectedPreset)
   const baseConfig = preset?.baseConfig ?? {}
@@ -32,8 +39,8 @@ export function buildConfigOverrides(values: WizardFormValues): Record<string, u
   if (values.styleguide.trim()) config.styleguide = values.styleguide.trim()
   if (values.editingLanguage.trim()) config.editing_language = values.editingLanguage.trim()
   if (values.outputLanguages.length > 0) config.output_languages = values.outputLanguages
-  if (parsedStartPage !== undefined) config.start_page = parsedStartPage
-  if (parsedEndPage !== undefined) config.end_page = parsedEndPage
+  if (validPageRange && parsedStartPage !== undefined) config.start_page = parsedStartPage
+  if (validPageRange && parsedEndPage !== undefined) config.end_page = parsedEndPage
   if (values.imageSegmentation && values.segmentationMinSide.trim()) {
     const n = Number(values.segmentationMinSide.trim())
     if (!isNaN(n)) config.image_segmentation = { min_side: n }

apps/studio/src/components/wizard/step1BasicInfo/PageRange.tsx

@@ -1,4 +1,3 @@
-// TODO: Add translations
 import { useStore } from "@tanstack/react-form"
 import { useWizardForm } from "@/components/wizard/wizardForm"
 import { RangeSlider } from "@/components/wizard/shared/RangeSlider"