Enhance graph editor: fullscreen bg, add-entity focus, color picker fix, UI polish

- Move bg-anim canvas into graph container during fullscreen so dynamic background is visible
- Watch for new entity creation from graph add menu and auto-navigate to it after reload
- Position color picker at click coordinates instead of 0,0
- Replace test/preview play triangle with eye icon to distinguish from start/stop
- Always use port-aware bezier curves for edges instead of ELK routing
- Add fullscreen and add-entity buttons to toolbar with keyboard shortcuts (F11, +)
- Add confirmation dialog for relayout when manual positions exist
- Remove node body stroke, keep only color bar; add per-node color picker
- Clamp toolbar position on load to prevent off-screen drift
- Add graph tab to getting-started tutorial
- Add WASD/arrow spatial navigation, ESC reset, keyboard shortcuts

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

server/src/wled_controller/static/css/graph-editor.css

@@ -256,8 +256,7 @@
 
 .graph-node-body {
     fill: var(--card-bg);
-    stroke: var(--border-color);
-    stroke-width: 1;
+    stroke: none;
     rx: 8;
     ry: 8;
     transition: stroke 0.15s;
@@ -265,6 +264,7 @@
 
 .graph-node:hover .graph-node-body {
     stroke: var(--text-secondary);
+    stroke-width: 1;
 }
 
 .graph-node.selected .graph-node-body {
@@ -561,6 +561,7 @@
 
 .graph-node.orphan .graph-node-body {
     stroke: var(--warning-color);
+    stroke-width: 1;
     stroke-dasharray: 4 3;
 }
 
@@ -679,6 +680,77 @@
 
 /* ── Loading overlay for relayout ── */
 
+/* ── Add entity menu ── */
+
+.graph-add-entity-menu {
+    position: absolute;
+    z-index: 30;
+    background: var(--card-bg);
+    border: 1px solid var(--border-color);
+    border-radius: 10px;
+    box-shadow: 0 8px 24px var(--shadow-color);
+    padding: 6px;
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 2px;
+    min-width: 280px;
+}
+
+.graph-add-entity-item {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    padding: 8px 10px;
+    border: none;
+    background: transparent;
+    color: var(--text-color);
+    font-size: 0.8rem;
+    font-family: inherit;
+    text-align: left;
+    border-radius: 6px;
+    cursor: pointer;
+    transition: background 0.1s;
+    white-space: nowrap;
+}
+
+.graph-add-entity-item:hover {
+    background: var(--bg-secondary);
+}
+
+.graph-add-entity-dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 2px;
+    flex-shrink: 0;
+}
+
+.graph-add-entity-icon {
+    font-size: 1rem;
+    flex-shrink: 0;
+}
+
+/* ── Fullscreen mode ── */
+
+.graph-container:fullscreen {
+    background: var(--bg-color);
+    height: 100vh;
+}
+
+.graph-container:fullscreen #bg-anim-canvas {
+    position: absolute;
+    inset: 0;
+    width: 100%;
+    height: 100%;
+    z-index: 0;
+}
+
+.graph-container:fullscreen .graph-svg {
+    position: relative;
+    z-index: 1;
+}
+
+/* ── Loading overlay for relayout ── */
+
 .graph-loading-overlay {
     position: absolute;
     inset: 0;