Fix color synchronization between admin panel and frontend

Fixed field name mismatch causing colors to display incorrectly:
- Frontend uses 'bojaHex' while backend expects 'boja_hex'
- Added bidirectional field transformation in API service layer
- Ensures hex color codes are properly saved and retrieved
- Also prevents editing of Bambu Lab predefined color hex codes

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/services/api.ts

@@ -70,16 +70,32 @@ export const colorService = {
 export const filamentService = {
   getAll: async () => {
     const response = await api.get('/filaments');
-    return response.data;
+    // Transform boja_hex to bojaHex for frontend compatibility
+    return response.data.map((f: any) => ({
+      ...f,
+      bojaHex: f.boja_hex || f.bojaHex
+    }));
   },
   
   create: async (filament: any) => {
-    const response = await api.post('/filaments', filament);
+    // Transform bojaHex to boja_hex for backend
+    const data = {
+      ...filament,
+      boja_hex: filament.bojaHex || filament.boja_hex
+    };
+    delete data.bojaHex; // Remove the frontend field
+    const response = await api.post('/filaments', data);
     return response.data;
   },
   
   update: async (id: string, filament: any) => {
-    const response = await api.put(`/filaments/${id}`, filament);
+    // Transform bojaHex to boja_hex for backend
+    const data = {
+      ...filament,
+      boja_hex: filament.bojaHex || filament.boja_hex
+    };
+    delete data.bojaHex; // Remove the frontend field
+    const response = await api.put(`/filaments/${id}`, data);
     return response.data;
   },