Improve ESP-NOW messaging and tab defaults

- Use shared ESPNOW payload limit and message splitting
- Expand default tab names and add flash/build artifacts.

Made-with: Cursor

build_static/styles.css

@@ -0,0 +1,37 @@
+/* General tab styles */
+.tabs {
+    display: flex;
+    justify-content: center;
+    margin-bottom: 20px;
+}
+
+.tab {
+    padding: 10px 20px;
+    margin: 0 10px;
+    cursor: pointer;
+    background-color: #f1f1f1;
+    border: 1px solid #ccc;
+    border-radius: 4px;
+    transition: background-color 0.3s ease;
+}
+
+.tab:hover {
+    background-color: #ddd;
+}
+
+.tab.active {
+    background-color: #ccc;
+}
+
+.tab-content {
+    display: flex;
+    justify-content: center;
+}
+
+.tab-pane {
+    display: none;
+}
+
+.tab-pane.active {
+    display: block;
+}