fix(admin): prevent model selection reset by using onSubmit instead of form action

Using form action in Next.js triggers automatic router cache revalidation,
causing the server component to re-render and remount the client component,
which resets all useState values. Switching to onSubmit with e.preventDefault()
prevents this behavior while preserving full functionality.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

keep-notes/app/(main)/admin/settings/admin-settings-form.tsx

@@ -169,20 +169,6 @@ export function AdminSettingsForm({ config }: { config: Record<string, string> }
         toast.error(t('admin.ai.updateFailed') + ': ' + result.error)
       } else {
         toast.success(t('admin.ai.updateSuccess'))
-        setTagsProvider(tagsProv)
-        setEmbeddingsProvider(embedProv)
-        if (tagsModel) setSelectedTagsModel(tagsModel)
-        if (embedModel) setSelectedEmbeddingModel(embedModel)
-
-        // Refresh models after save if Ollama is selected
-        if (tagsProv === 'ollama') {
-          const url = data.OLLAMA_BASE_URL_TAGS || config.OLLAMA_BASE_URL || 'http://localhost:11434'
-          fetchOllamaModels('tags', url)
-        }
-        if (embedProv === 'ollama') {
-          const url = data.OLLAMA_BASE_URL_EMBEDDING || config.OLLAMA_BASE_URL || 'http://localhost:11434'
-          fetchOllamaModels('embeddings', url)
-        }
       }
     } catch (error: any) {
       setIsSaving(false)
@@ -235,7 +221,7 @@ export function AdminSettingsForm({ config }: { config: Record<string, string> }
           <CardTitle>{t('admin.security.title')}</CardTitle>
           <CardDescription>{t('admin.security.description')}</CardDescription>
         </CardHeader>
-        <form action={handleSaveSecurity}>
+        <form onSubmit={(e) => { e.preventDefault(); handleSaveSecurity(new FormData(e.currentTarget)) }}>
           <CardContent className="space-y-4">
             <div className="flex items-center space-x-2">
               <Checkbox
@@ -265,7 +251,7 @@ export function AdminSettingsForm({ config }: { config: Record<string, string> }
           <CardTitle>{t('admin.ai.title')}</CardTitle>
           <CardDescription>{t('admin.ai.description')}</CardDescription>
         </CardHeader>
-        <form action={handleSaveAI}>
+        <form onSubmit={(e) => { e.preventDefault(); handleSaveAI(new FormData(e.currentTarget)) }}>
           <CardContent className="space-y-6">
             <div className="space-y-4 p-4 border rounded-lg bg-primary/5 dark:bg-primary/10">
               <h3 className="text-base font-semibold flex items-center gap-2">
@@ -561,7 +547,7 @@ export function AdminSettingsForm({ config }: { config: Record<string, string> }
           <CardTitle>{t('admin.smtp.title')}</CardTitle>
           <CardDescription>{t('admin.smtp.description')}</CardDescription>
         </CardHeader>
-        <form action={handleSaveSMTP}>
+        <form onSubmit={(e) => { e.preventDefault(); handleSaveSMTP(new FormData(e.currentTarget)) }}>
           <CardContent className="space-y-4">
             <div className="grid grid-cols-2 gap-4">
               <div className="space-y-2">