Change search example to 3vgk.A

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/components/datasets/protein/ChainSearchInput.tsx

@@ -55,7 +55,7 @@ export const ChainSearchInput: React.FC<ChainSearchInputProps> = ({
       return { pdb_id: '', auth_asym_id: '', valid: false };
     }
 
-    // Accept formats: "3vgm.A", "3VGM:A", "3VGM_A", "3vgm A"
+    // Accept formats: "3vgk.A", "3VGK:A", "3VGK_A", "3vgk A"
     const separatorRegex = /[.\s:_]+/;
     const parts = trimmed.split(separatorRegex);
 
@@ -64,7 +64,7 @@ export const ChainSearchInput: React.FC<ChainSearchInputProps> = ({
         pdb_id: '',
         auth_asym_id: '',
         valid: false,
-        error: 'Format: PDB_ID + Chain (e.g., "3vgm.A", "3VGM:A", "3VGM_A")'
+        error: 'Format: PDB_ID + Chain (e.g., "3vgk.A", "3VGK:A", "3VGK_A")'
       };
     }
 
@@ -156,7 +156,7 @@ export const ChainSearchInput: React.FC<ChainSearchInputProps> = ({
       <label className="block">
         <span className="text-sm font-medium text-slate-900">Chain Identifier</span>
         <span className="block text-xs text-slate-500 mt-1">
-          Format: PDB ID + Chain (e.g., 3vgm.A, 3VGM:A, 3VGM_A, 3vgm A)
+          Format: PDB ID + Chain (e.g., 3vgk.A, 3VGK:A, 3VGK_A, 3vgk A)
         </span>
       </label>
       
@@ -166,7 +166,7 @@ export const ChainSearchInput: React.FC<ChainSearchInputProps> = ({
           className="flex-1 px-4 py-3 text-sm text-slate-900 bg-transparent rounded-lg outline-none placeholder:text-slate-400 disabled:bg-slate-50 disabled:cursor-not-allowed"
           value={value}
           onChange={(e) => onValueChange(e.target.value)}
-          placeholder="e.g., 3vgm.A"
+          placeholder="e.g., 3vgk.A"
           disabled={disabled}
         />