chore: prepare v1.0.0 release

app/api/upload/check/route.ts

@@ -5,6 +5,7 @@ import { classifyFileChanges } from '@/lib/diff-files'
 import { getModelFolderPath } from '@/lib/model-paths'
 import { ensurePreparedStagingAssets } from '@/lib/upload-staging'
 import { parseStagingRequestBody } from '@/lib/upload-request'
+import { getErrorMessage } from '@/lib/guards'
 
 export const runtime = 'nodejs'
 export const dynamic = 'force-dynamic'
@@ -23,7 +24,7 @@ export async function POST(req: NextRequest) {
     const body: unknown = await req.json()
     stagingId = parseStagingRequestBody(body).stagingId
   } catch (err) {
-    const message = err instanceof Error ? err.message : 'Erreur inconnue'
+    const message = getErrorMessage(err)
     return NextResponse.json({ success: false, error: message }, { status: 400 })
   }
 
@@ -56,7 +57,7 @@ export async function POST(req: NextRequest) {
 
     return NextResponse.json({ success: true, exists: false })
   } catch (err) {
-    const message = err instanceof Error ? err.message : 'Erreur inconnue'
+    const message = getErrorMessage(err)
     return NextResponse.json({ success: false, error: message }, { status: 500 })
   }
 }