Add error handling to localStorage operations (sugarlabs#5329)

Wrap localStorage.setItem() calls in try-catch blocks to prevent
crashes when storage is unavailable (e.g., private browsing mode,
quota exceeded, or security restrictions).

Modified files:
- js/themebox.js: Theme preference storage
- js/languagebox.js: Language preference storage
- js/widgets/reflection.js: Analysis report storage

All localStorage operations now gracefully handle errors with
console.warn logging, ensuring the application remains functional
even when storage fails.

Co-authored-by: Vanshika <vanshika@198625@gmail.com>

Author: vanshika2720

js/languagebox.js

@@ -234,7 +234,11 @@ class LanguageBox {
                 this._language = this._language.split("-")[0];
             }
 
-            localStorage.setItem("languagePreference", this._language);
+            try {
+                localStorage.setItem("languagePreference", this._language);
+            } catch (e) {
+                console.warn("Could not save language preference:", e);
+            }
             this.activity.textMsg(_("Music Blocks is already set to this language."));
         } else {
             this.activity.storage.languagePreference = this._language;

js/themebox.js

@@ -263,7 +263,11 @@ class ThemeBox {
         } else {
             // Save preference to localStorage
             this.activity.storage.themePreference = this._theme;
-            localStorage.setItem("themePreference", this._theme);
+            try {
+                localStorage.setItem("themePreference", this._theme);
+            } catch (e) {
+                console.warn("Could not save theme preference:", e);
+            }
 
             // Apply theme instantly instead of reloading
             this.applyThemeInstantly();

js/widgets/reflection.js

@@ -575,7 +575,11 @@ class ReflectionMatrix {
      */
     saveReport(data) {
         const key = "musicblocks_analysis";
-        localStorage.setItem(key, data.response);
+        try {
+            localStorage.setItem(key, data.response);
+        } catch (e) {
+            console.warn("Could not save analysis report to localStorage:", e);
+        }
         console.log("Conversation saved in localStorage.");
     }