Add CACHE_STATUS UART poll and dashboard live stream.

Combine cached accel and tap in one low-overhead master command for ~16 ms
host polling. The dashboard uses a single live-stream toggle plus per-slave
accel-stream controls; fix live_stream state so polling is not cleared every
slow client refresh.

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

goTool/webui/index.html

@@ -290,10 +290,17 @@
             </div>
           </div>
           <p class="text-muted small px-3 pt-2 mb-0">
-            Accel-Stream pro Slave per „Stream an“ aktivieren (~16&nbsp;ms ESP-NOW). Tap-Notify (S/D/T)
-            konfiguriert den Slave; „Empfang an“ startet das Abfragen von Tap-Events (~16&nbsp;ms).
+            <strong>Live-Stream</strong> startet die schnelle <code>CACHE_STATUS</code>-Abfrage (~16&nbsp;ms).
+            Pro Slave <strong>Accel</strong> aktiviert den ESP-NOW-Accel-Stream; Tap-Notify (S/D/T) steuert
+            die Tap-Arten auf dem Slave.
           </p>
           <div class="px-3 pb-2 d-flex flex-wrap gap-2 align-items-center">
+            <button type="button"
+                    class="btn btn-sm"
+                    :class="state.live_stream ? 'btn-warning' : 'btn-success'"
+                    @click="setLiveStream(!state.live_stream)"
+                    :disabled="busy || !state.uart_connected || !(state.clients || []).length"
+                    x-text="state.live_stream ? 'Live-Stream aus' : 'Live-Stream an'"></button>
             <span class="text-muted small">Tap alle Slaves:</span>
             <label class="tap-toggle"><input type="checkbox" x-model="allTapSingle" :disabled="busy"> S</label>
             <label class="tap-toggle"><input type="checkbox" x-model="allTapDouble" :disabled="busy"> D</label>
@@ -316,7 +323,7 @@
                     <th>Deadzone</th>
                     <th>Accel (LSB)</th>
                     <th>Akku</th>
-                    <th>Stream</th>
+                    <th>Accel</th>
                     <th>Tap-Notify</th>
                     <th>Tap</th>
                     <th>Aktion</th>
@@ -350,7 +357,8 @@
                                 :class="c.accel_stream ? 'btn-warning' : 'btn-outline-success'"
                                 @click="setAccelStream(c.id, !c.accel_stream)"
                                 :disabled="busy || !state.uart_connected || !c.available"
-                                x-text="c.accel_stream ? 'Aus' : 'An'"></button>
+                                x-text="c.accel_stream ? 'Aus' : 'An'"
+                                title="ESP-NOW Accel-Stream auf Slave"></button>
                       </td>
                       <td>
                         <div class="d-flex flex-wrap gap-1 align-items-center">
@@ -375,16 +383,7 @@
                         </div>
                       </td>
                       <td>
-                        <div class="d-flex flex-wrap gap-1 align-items-center">
-                          <button type="button"
-                                  class="btn btn-sm"
-                                  :class="c.tap_receive ? 'btn-warning' : 'btn-outline-success'"
-                                  @click="setTapReceive(c.id, !c.tap_receive)"
-                                  :disabled="busy || !state.uart_connected || !c.available || !tapNotifyAny(c)"
-                                  x-text="c.tap_receive ? 'Aus' : 'An'"
-                                  title="Tap-Events vom Master abfragen"></button>
-                          <span :class="tapCellClass(c)" x-text="formatLastTap(c)" :title="tapTitle(c)"></span>
-                        </div>
+                        <span :class="tapCellClass(c)" x-text="formatLastTap(c)" :title="tapTitle(c)"></span>
                       </td>
                       <td>
                         <div class="d-flex flex-wrap gap-1 align-items-center">
@@ -779,12 +778,14 @@
           return t;
         },
         formatAccel(c) {
+          if (!this.state?.live_stream) return '—';
           if (!c?.accel_stream) return '—';
           if (!c?.accel_valid) return '…';
           return `${c.accel_x} / ${c.accel_y} / ${c.accel_z}`;
         },
         accelTitle(c) {
-          if (!c?.accel_stream) return 'Accel-Stream nicht aktiviert';
+          if (!this.state?.live_stream) return 'Live-Stream aus — oben einschalten';
+          if (!c?.accel_stream) return 'Accel-Stream für diesen Slave nicht aktiv';
           if (!c?.accel_valid) return 'Warte auf erste ESP-NOW Samples…';
           const age = c.accel_age_ms != null ? `${c.accel_age_ms} ms alt` : '';
           return `x=${c.accel_x} y=${c.accel_y} z=${c.accel_z} (raw LSB, ±2g)${age ? ' · ' + age : ''}`;
@@ -820,7 +821,7 @@
           return d;
         },
         formatLastTap(c) {
-          if (!c?.tap_receive) return '—';
+          if (!this.state?.live_stream) return '—';
           if (!this.tapNotifyAny(c)) return '—';
           const labels = { single: 'Single', double: 'Double', triple: 'Triple' };
           const d = this.activeTapDisplay(c);
@@ -829,7 +830,7 @@
           return labels[c.last_tap] || c.last_tap;
         },
         tapTitle(c) {
-          if (!c?.tap_receive) return 'Tap-Empfang aus — „An“ klicken';
+          if (!this.state?.live_stream) return 'Live-Stream aus';
           if (!this.tapNotifyAny(c)) return 'Tap-Notify nicht konfiguriert (S/D/T)';
           const d = this.activeTapDisplay(c);
           if (!d && !c?.last_tap) return 'Warte auf Tap-Event…';
@@ -1080,11 +1081,47 @@
         async setMasterDeadzone() {
           await this.setDeadzone(0, this.masterDz);
         },
+        patchLiveStream(enabled) {
+          let clients = this.state.clients || [];
+          if (!enabled) {
+            clients = clients.map((c) => ({
+              ...c,
+              accel_valid: false,
+              accel_x: 0,
+              accel_y: 0,
+              accel_z: 0,
+              accel_age_ms: 0,
+              last_tap: '',
+              last_tap_at: 0
+            }));
+            this.tapDisplay = {};
+          }
+          this.state = { ...this.state, live_stream: enabled, clients };
+        },
+        async setLiveStream(enable) {
+          this.busy = true;
+          try {
+            const r = await fetch('/api/live-stream', {
+              method: 'PUT',
+              headers: { 'Content-Type': 'application/json' },
+              body: JSON.stringify({ enable })
+            });
+            const data = await r.json();
+            if (!r.ok || !data.success) {
+              this.flash(data.error || 'Live-Stream fehlgeschlagen', false);
+              return;
+            }
+            this.patchLiveStream(!!data.enabled);
+            this.flash(`Live-Stream ${data.enabled ? 'an' : 'aus'}`, true);
+          } catch (e) {
+            this.flash(String(e), false);
+          } finally {
+            this.busy = false;
+          }
+        },
         patchClientAccelStream(clientId, enabled) {
           const clients = (this.state.clients || []).map((c) => {
-            if (c.id !== clientId) {
-              return c;
-            }
+            if (c.id !== clientId) return c;
             const next = { ...c, accel_stream: enabled };
             if (!enabled) {
               next.accel_valid = false;
@@ -1103,7 +1140,7 @@
             const r = await fetch(`/api/clients/${clientId}/accel-stream`, {
               method: 'PUT',
               headers: { 'Content-Type': 'application/json' },
-              body: JSON.stringify({ enable: enable })
+              body: JSON.stringify({ enable })
             });
             const data = await r.json();
             if (!r.ok || !data.success) {
@@ -1182,40 +1219,6 @@
             this.busy = false;
           }
         },
-        patchClientTapReceive(clientId, enabled) {
-          const clients = (this.state.clients || []).map((c) => {
-            if (c.id !== clientId) return c;
-            const next = { ...c, tap_receive: enabled };
-            if (!enabled) {
-              next.last_tap = '';
-              next.last_tap_at = 0;
-              delete this.tapDisplay[clientId];
-            }
-            return next;
-          });
-          this.state = { ...this.state, clients };
-        },
-        async setTapReceive(clientId, enable) {
-          this.busy = true;
-          try {
-            const r = await fetch(`/api/clients/${clientId}/tap-receive`, {
-              method: 'PUT',
-              headers: { 'Content-Type': 'application/json' },
-              body: JSON.stringify({ enable })
-            });
-            const data = await r.json();
-            if (!r.ok || !data.success) {
-              this.flash(data.error || `Tap-Empfang Slave ${clientId} fehlgeschlagen`, false);
-              return;
-            }
-            this.patchClientTapReceive(clientId, !!data.enabled);
-            this.flash(`Slave ${clientId}: Tap-Empfang ${data.enabled ? 'an' : 'aus'}`, true);
-          } catch (e) {
-            this.flash(String(e), false);
-          } finally {
-            this.busy = false;
-          }
-        },
         async setDeadzoneAll(deadzone) {
           if (deadzone == null || deadzone < 0) {
             this.flash('Ungültiger Deadzone-Wert', false);