Add automatic nearby discovery and simplify device presence UI

apps/web/src/style.css

@@ -2604,15 +2604,6 @@ a.button {
 .devices-stage {
   margin: 34px auto 0;
 }
-.stage-heading {
-  text-align: center;
-  margin-bottom: 32px;
-}
-.stage-heading h1 {
-  font-size: 26px;
-  letter-spacing: -0.04em;
-  font-weight: 600;
-}
 .devices-stage .section-heading h2 {
   font-size: 13px;
   font-weight: 500;
@@ -2725,12 +2716,6 @@ a.button {
   .devices-stage {
     margin-top: 26px;
   }
-  .stage-heading {
-    margin-bottom: 26px;
-  }
-  .stage-heading h1 {
-    font-size: 23px;
-  }
   .devices-stage .peer-grid {
     grid-template-columns: repeat(2, minmax(0, 1fr));
     gap: 12px;
@@ -2780,7 +2765,7 @@ a.button {
 }
 @media (max-width: 639px) {
   .devices-stage .peer-grid.device-count-1 {
-    grid-template-columns: minmax(0, 190px);
+    grid-template-columns: minmax(0, 1fr);
   }
 }
 .devices-stage .empty-peers {
@@ -2983,12 +2968,6 @@ a.button {
 .devices-stage {
   margin-top: 28px;
 }
-.stage-heading {
-  margin-bottom: 24px;
-}
-.stage-heading h1 {
-  font-size: 21px;
-}
 .device-footer {
   margin-top: 38px;
   padding: 20px 0;
@@ -3090,9 +3069,6 @@ a.button {
     min-height: 166px;
     padding: 18px 12px;
   }
-  .stage-heading h1 {
-    font-size: 20px;
-  }
 }
 .footer-device-summary .footer-device-code {
   font-size: 10px;
@@ -3154,3 +3130,103 @@ a.button {
     height: 520px;
   }
 }
+
+/* Presence changes animate once; idle discovery has no running animation. */
+.devices-stage .peer-grid {
+  position: relative;
+}
+.devices-stage .peer-model {
+  color: var(--muted);
+  font-size: 10px;
+  margin-top: 3px;
+  overflow-wrap: anywhere;
+}
+.devices-stage .empty-devices {
+  text-align: center;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+}
+.devices-stage .empty-devices h3 {
+  font-size: 17px;
+  margin: 0;
+}
+.devices-stage .empty-devices p {
+  font-size: 13px;
+  color: var(--muted);
+  margin: 0;
+}
+.initial-device-loading {
+  padding: 32px 0;
+  max-width: 360px;
+  margin: auto;
+  text-align: center;
+  color: var(--muted);
+  font-size: 13px;
+}
+.peer-skeleton {
+  min-height: 180px;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 18px;
+  pointer-events: none;
+}
+.peer-skeleton i,
+.peer-skeleton span,
+.peer-skeleton small {
+  display: block;
+  background: var(--line);
+  border-radius: 8px;
+}
+.peer-skeleton i {
+  width: 42px;
+  height: 42px;
+}
+.peer-skeleton span {
+  width: 65%;
+  height: 16px;
+}
+.peer-skeleton small {
+  width: 42%;
+  height: 10px;
+}
+.device-enter-active {
+  transition:
+    opacity 180ms ease,
+    transform 180ms ease;
+}
+.device-enter-from {
+  opacity: 0;
+  transform: translateY(6px) scale(0.96);
+}
+.device-move {
+  transition: transform 220ms ease;
+}
+.device-leave-active {
+  position: absolute;
+  pointer-events: none;
+  animation: device-pop-away 240ms ease-in forwards;
+}
+@keyframes device-pop-away {
+  25% {
+    transform: scale(1.035);
+  }
+  100% {
+    opacity: 0;
+    transform: translateY(-6px) scale(0.82);
+  }
+}
+@media (prefers-reduced-motion: reduce) {
+  .device-enter-active,
+  .device-move {
+    transition: none;
+  }
+  .device-leave-active {
+    animation: none;
+    opacity: 0;
+  }
+}