Enable host OTA over BLE and harden ESP-NOW slave distribution.

Allow the same staged firmware upload path on BLE as UART, fix distribute stack/event-group crashes, and recover sticky slave OTA sessions instead of failing with err=4.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/webui/index.html

@@ -788,23 +788,23 @@
         </div>
       </section>
 
-      <section class="col-12" x-show="isUARTHost() || !hostUp()">
+      <section class="col-12">
         <div class="card">
           <div class="card-header">Firmware OTA (A/B)</div>
           <div class="card-body">
             <p class="text-muted small mb-3">
-              Lädt eine <code>.bin</code> auf den Master (nur UART-Host, DIP8=0), danach verteilt die Firmware automatisch per ESP-NOW an alle verfügbaren Slaves.
-              Während des Uploads pausiert das Live-Polling. Bei BLE-Host ist OTA nicht verfügbar.
+              Lädt eine <code>.bin</code> auf den Master (UART oder BLE), danach verteilt die Firmware automatisch per ESP-NOW an alle verfügbaren Slaves.
+              Während des Uploads pausiert das Live-Polling. BLE braucht ATT MTU ≥ 219.
             </p>
             <div class="mb-3">
               <input type="file" class="form-control form-control-sm" accept=".bin,application/octet-stream"
                      @change="otaFile = $event.target.files[0]"
-                     :disabled="ota.active || busy || !isUARTHost()">
+                     :disabled="ota.active || busy || !hostUp()">
             </div>
             <div class="d-flex flex-wrap gap-2 align-items-center mb-2">
               <button type="button" class="btn btn-primary btn-sm"
                       @click="uploadOTA()"
-                      :disabled="ota.active || busy || !isUARTHost() || !otaFile">
+                      :disabled="ota.active || busy || !hostUp() || !otaFile">
                 Firmware hochladen
               </button>
               <span class="text-muted small" x-show="otaFile"
@@ -812,7 +812,7 @@
             </div>
             <div class="ota-progress-panel mt-3"
                  x-show="ota.active || ota.phase === 'distributing' || ota.phase === 'done' || ota.phase === 'error'">
-              <p class="small text-muted mb-2">Master (UART)</p>
+              <p class="small text-muted mb-2">Master (Host)</p>
               <table class="table table-sm pp-table ota-progress-table mb-3">
                 <tbody>
                   <tr>
@@ -845,7 +845,8 @@
                 Slaves (ESP-NOW)
                 <span x-text="'(' + otaSlaveRows().length + ')'"></span>
               </p>
-              <p class="small text-muted mb-2" x-show="ota.message && ota.step === 'slaves'"
+              <p class="small text-muted mb-2"
+                 x-show="ota.step === 'slaves' && otaSlaveRows().length > 0 && ota.message"
                  x-text="ota.message"></p>
               <table class="table table-sm pp-table ota-progress-table mb-2">
                 <tbody>
@@ -877,9 +878,8 @@
                     </tr>
                   </template>
                   <tr x-show="otaSlaveRows().length === 0">
-                    <td colspan="2" class="text-muted small py-3">
-                      Warte auf Slave-Fortschritt…
-                    </td>
+                    <td colspan="2" class="text-muted small py-3"
+                        x-text="otaDistEmptyHint()"></td>
                   </tr>
                 </tbody>
               </table>
@@ -1422,7 +1422,19 @@
           if (status === 1 || status === 2) return 'bg-secondary';
           return 'bg-info';
         },
+        otaDistEmptyHint() {
+          const msg = this.ota.message || '';
+          if (/übersprungen/i.test(msg)) {
+            return msg;
+          }
+          if (this.ota.phase === 'done') {
+            return 'Keine Slave-Verteilung gemeldet.';
+          }
+          return 'Warte auf Slave-Fortschritt…';
+        },
         otaSlaveRows() {
+          // Only real OTA progress — do not invent placeholder rows from the
+          // client list (that contradicted "keine Slaves / übersprungen").
           const details = this.mergeSlaveDetails(this.ota.slaveDetails);
           const ids = new Set(Object.keys(details).map(Number).filter(id => !Number.isNaN(id)));
           for (const [k, v] of Object.entries(this.ota.slaveProgress || {})) {
@@ -1454,21 +1466,6 @@
               bytesLabel: total ? `${bytes} / ${total} bytes` : `${bytes} bytes`
             });
           }
-          if (rows.length === 0 && (this.ota.phase === 'distributing' || this.ota.step === 'slaves')) {
-            const targets = (this.state.clients || []).filter(c => c.available);
-            const limit = this.ota.slaves > 0 ? this.ota.slaves : targets.length;
-            for (const c of targets.slice(0, limit)) {
-              rows.push({
-                id: c.id,
-                mac: c.mac ? this.formatMac(c.mac) : '—',
-                percent: 0,
-                status: 1,
-                statusLabel: this.otaSlaveStatusLabel(1),
-                barClass: this.otaSlaveBarClass(1),
-                bytesLabel: '—'
-              });
-            }
-          }
           return rows;
         },
         applyOTAProgress(p) {