feat(frontend): update layout, UI components, stores, and API route

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/app.css

@@ -144,3 +144,14 @@
 .scrollbar-hide::-webkit-scrollbar {
 	display: none;
 }
+
+/* Hide number input spinners across the app */
+input[type='number'].no-spin {
+	-moz-appearance: textfield;
+	appearance: textfield;
+}
+input[type='number'].no-spin::-webkit-outer-spin-button,
+input[type='number'].no-spin::-webkit-inner-spin-button {
+	-webkit-appearance: none;
+	margin: 0;
+}