Add form-fill UIWorker example

A ReplyToolMixin UIWorker that fills inputs (fills) and toggles checkboxes /
presses submit (click) by voice — the state-changing half of the standard
action set.

examples/multi-worker/ui-worker/form-fill/client/styles.css

@@ -0,0 +1,207 @@
+:root {
+  color-scheme: light;
+  font-family: system-ui, -apple-system, sans-serif;
+  --border: #d4d4d8;
+  --border-focus: #3b82f6;
+  --muted: #71717a;
+  --bg: #fafafa;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  background: var(--bg);
+  color: #18181b;
+}
+
+header {
+  position: sticky;
+  top: 0;
+  z-index: 10;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 1rem 1.5rem;
+  border-bottom: 1px solid var(--border);
+  background: #fff;
+}
+
+header h1 {
+  font-size: 1.125rem;
+  margin: 0;
+}
+
+#connect {
+  padding: 0.5rem 1rem;
+  border: 1px solid var(--border);
+  background: #fff;
+  border-radius: 6px;
+  cursor: pointer;
+  font-size: 0.875rem;
+}
+
+#connect:hover {
+  background: #f4f4f5;
+}
+
+#connect[data-state="connected"] {
+  background: #ef4444;
+  color: white;
+  border-color: #ef4444;
+}
+
+main {
+  max-width: 640px;
+  margin: 0 auto;
+  padding: 2rem 1.5rem 4rem;
+}
+
+form h2 {
+  margin: 0 0 0.5rem;
+  font-size: 1.5rem;
+}
+
+.hint {
+  margin: 0 0 1.5rem;
+  font-size: 0.9375rem;
+  line-height: 1.5;
+  color: var(--muted);
+}
+
+fieldset {
+  margin: 0 0 1.5rem;
+  padding: 1rem 1.25rem 1.25rem;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: #fff;
+}
+
+legend {
+  padding: 0 0.5rem;
+  font-size: 0.8125rem;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  color: var(--muted);
+}
+
+.field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.25rem;
+  margin-top: 0.875rem;
+}
+
+.field:first-child {
+  margin-top: 0;
+}
+
+.field label {
+  font-size: 0.875rem;
+  font-weight: 500;
+  color: #27272a;
+}
+
+.field input[type="text"],
+.field input[type="email"],
+.field input[type="tel"],
+.field textarea {
+  font: inherit;
+  font-size: 1rem;
+  padding: 0.5rem 0.625rem;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: #fff;
+  width: 100%;
+  scroll-margin-top: 5rem;
+  transition:
+    border-color 0.15s,
+    box-shadow 0.15s,
+    background 0.4s;
+}
+
+.field input:focus,
+.field textarea:focus {
+  outline: none;
+  border-color: var(--border-focus);
+  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
+}
+
+/* Brief flash when the agent fills a field, so the user notices the
+   write. The CSS class is added by the set_input_value handler and
+   removed after the animation. */
+@keyframes field-fill-flash {
+  0% {
+    background: #fef3c7;
+  }
+  100% {
+    background: #fff;
+  }
+}
+
+.field input.fill-flash,
+.field textarea.fill-flash {
+  animation: field-fill-flash 1.2s ease-out;
+}
+
+.field textarea {
+  resize: vertical;
+}
+
+.checkbox-field {
+  flex-direction: row;
+  align-items: center;
+  gap: 0.5rem;
+}
+
+.checkbox-field label {
+  font-weight: 400;
+}
+
+.actions {
+  display: flex;
+  gap: 1rem;
+  align-items: center;
+}
+
+#submit {
+  font: inherit;
+  font-size: 0.9375rem;
+  font-weight: 500;
+  padding: 0.625rem 1.25rem;
+  background: #18181b;
+  color: white;
+  border: 1px solid #18181b;
+  border-radius: 6px;
+  cursor: pointer;
+}
+
+#submit:hover {
+  background: #27272a;
+}
+
+#form-status {
+  font-size: 0.875rem;
+  color: var(--muted);
+}
+
+#status {
+  position: fixed;
+  bottom: 1rem;
+  right: 1rem;
+  padding: 0.5rem 0.75rem;
+  border-radius: 6px;
+  font-size: 0.8125rem;
+  background: #18181b;
+  color: white;
+  opacity: 0;
+  transition: opacity 0.2s;
+  pointer-events: none;
+}
+
+#status[data-show="1"] {
+  opacity: 1;
+}