perf: Optimize recommendation system and improve error handling

- Fix N+1 query problem in preset package fetching
  * Search with limit 5 to find best matches
  * Case-insensitive package name matching
  * Fallback to most popular when no exact match

- Improve category filtering accuracy
  * Update category mapping to match database schema
  * Remove duplicate packages in category fetching
  * Better distribution across categories

- Add version control for localStorage profile
  * Support future schema migrations
  * Auto-migrate old profiles to new version
  * Persist version in localStorage

- Enhance error handling
  * Specific error messages for 400/500/404 responses
  * Network error detection
  * User-friendly error messages in UI

- Fix OS detection fallback
  * Default to ubuntu when detection returns unknown
  * Prevent empty OS selection in onboarding

- Add better API validation
  * Explicit limit range validation (1-50)
  * Clear error messages for invalid inputs

src/hooks/useRecommendationProfile.ts

@@ -57,11 +57,14 @@ function detectOS(): string {
   return "unknown";
 }
 
+const CURRENT_PROFILE_VERSION = 1;
+
 /**
  * Get default user profile
  */
 function getDefaultProfile(): UserProfile {
   return {
+    version: CURRENT_PROFILE_VERSION,
     categories: [],
     detectedOS: detectOS(),
     selectedOS: undefined,
@@ -86,6 +89,13 @@ export function useRecommendationProfile() {
       if (stored) {
         const parsed = JSON.parse(stored) as UserProfile;
 
+        // Handle version migration
+        if (!parsed.version || parsed.version < CURRENT_PROFILE_VERSION) {
+          console.log("Migrating profile from version", parsed.version || 0, "to", CURRENT_PROFILE_VERSION);
+          // Add migration logic here when schema changes in the future
+          parsed.version = CURRENT_PROFILE_VERSION;
+        }
+
         // Update detectedOS if it changed
         const currentOS = detectOS();
         if (parsed.detectedOS !== currentOS) {
@@ -93,6 +103,8 @@ export function useRecommendationProfile() {
         }
 
         setProfile(parsed);
+        // Save migrated profile
+        localStorage.setItem(STORAGE_KEY, JSON.stringify(parsed));
       } else {
         // First time user - save default profile
         const defaultProfile = getDefaultProfile();