ui: add BMS scan button

firmware/esp32/overland-controller/overland-controller.ino

@@ -639,12 +639,15 @@ button[onclick^="scan"]{
             <input id="bmsAddressTypeInput" placeholder="Address type: public or random">
             <div class="btnrow">
               <button class="save" onclick="saveBmsFullConfig()">Save BMS</button>
+              <button onclick="scanBmsDevices()">Scan BMS</button>
               <button class="off" onclick="setBmsEnabled(false)">Disable BMS</button>
             </div>
             <div class="btnrow">
               <button onclick="setBmsEnabled(true)">Enable BMS</button>
             </div>
             <div class="row"><span class="muted">BMS Polling</span><span class="v" id="bmsEnabledText">--</span></div>
+            <div id="bmsScanStatus" class="muted"></div>
+            <div id="bmsScanResults"></div>
           </div>
         </section>
       </div>
@@ -1070,6 +1073,46 @@ async function saveDeviceConfig(){
   clearConfigTouched(["deviceNameInput"]);
 }
 
+
+async function scanBmsDevices(){
+  const status=$("bmsScanStatus");
+  const box=$("bmsScanResults");
+  if(status) status.textContent="Scanning for BLE BMS devices...";
+  if(box) box.innerHTML="";
+
+  try{
+    const res=await fetch(api("/bms/scan"),{method:"POST"});
+    const data=await res.json();
+    const devices=data.devices||[];
+
+    if(status) status.textContent=devices.length ? `Found ${devices.length} device(s).` : "No BLE devices found.";
+
+    if(box){
+      box.innerHTML=devices.map(d=>`
+        <div class="configrow">
+          <div>
+            <div><b>${d.name||"Unnamed BLE device"}</b></div>
+            <div class="muted">${d.address||""} RSSI ${d.rssi??"--"}</div>
+          </div>
+          <button onclick="selectScannedBms('${d.address||""}','${(d.name||"BMS").replace(/'/g,"\\'")}')">Select</button>
+        </div>
+      `).join("");
+    }
+  }catch(e){
+    if(status) status.textContent="BMS scan failed.";
+  }
+}
+
+function selectScannedBms(address,name){
+  setConfigValue("bmsNameInput",name||"BMS",true);
+  setConfigValue("bmsAddressInput",address||"",true);
+  setConfigValue("bmsAddressTypeInput","public",true);
+  markConfigFieldTouched("bmsNameInput");
+  markConfigFieldTouched("bmsAddressInput");
+  markConfigFieldTouched("bmsAddressTypeInput");
+}
+
+
 async function saveBmsFullConfig(){
   const name=$("bmsNameInput")?.value.trim()||"BMS";
   const address=$("bmsAddressInput")?.value.trim()||"";