Lib: Move form stuff into form/ directory

src/lib/components/form/Input.svelte

@@ -0,0 +1,26 @@
+<script lang="ts">
+  import type { Snippet } from "svelte";
+  import type { HTMLInputAttributes } from "svelte/elements";
+
+  interface InputProps extends HTMLInputAttributes {
+    children: Snippet;
+
+    /** Manually set the label width, to align multiple inputs vertically. Supply value in CSS units. */
+    labelwidth?: string;
+
+    /** The type of the input element, e.g. "text". */
+    type?: string;
+  }
+
+  let { children, labelwidth = "auto", type = "text", ...restProps }: InputProps = $props();
+</script>
+
+<div class="input-group input-group-divider grid-cols-[auto_1fr_auto]">
+  <div
+    class="input-group-shim select-none text-nowrap text-neutral-900"
+    style="width: {labelwidth};"
+  >
+    {@render children()}
+  </div>
+  <input {type} {...restProps} />
+</div>