Improve device cards, stream/template UI, and add PP template testing

- Move WLED UI button into URL badge as clickable link on device cards
- Remove version label from device cards
- Show PP template name on processed stream cards
- Display filter chain as pills on processing template cards
- Add processing template test with source stream selector
- Pre-load PP templates when viewing streams to fix race condition
- Add ESC key handling for all modals
- Add filter chain CSS styles

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/style.css

@@ -243,6 +243,7 @@ section {
     color: var(--primary-color);
 }
 
+
 .card-remove-btn {
     position: absolute;
     top: 10px;
@@ -284,6 +285,9 @@ section {
 }
 
 .device-url-badge {
+    display: inline-flex;
+    align-items: center;
+    gap: 4px;
     font-size: 0.7rem;
     font-weight: 400;
     color: var(--text-secondary);
@@ -292,6 +296,16 @@ section {
     border-radius: 10px;
     letter-spacing: 0.03em;
     font-family: monospace;
+    text-decoration: none;
+    transition: background 0.2s;
+}
+
+.device-url-badge:hover {
+    background: var(--text-muted);
+}
+
+.device-url-icon {
+    font-size: 0.6rem;
 }
 
 .card-subtitle {
@@ -1791,6 +1805,27 @@ input:-webkit-autofill:focus {
     margin-bottom: 8px;
 }
 
+.filter-chain {
+    display: flex;
+    align-items: center;
+    flex-wrap: wrap;
+    gap: 4px;
+    margin-bottom: 8px;
+}
+
+.filter-chain-item {
+    font-size: 0.7rem;
+    background: var(--border-color);
+    color: var(--text-secondary);
+    padding: 2px 8px;
+    border-radius: 10px;
+}
+
+.filter-chain-arrow {
+    font-size: 0.7rem;
+    color: var(--text-muted);
+}
+
 .template-config-details {
     margin: 12px 0;
     font-size: 13px;