feat(savings_goals/new): live previewable name avatar + ghost cancel + circular header icon

Replace the big square DS::FilledIcon next to the name input with a
small Savings::GoalAvatarComponent that previews the goal's avatar
(seeded color + first character of the typed name, updates live via
new stepper#nameChanged action).

Switch the modal header's target avatar from FilledIcon(size: lg,
rounded: false) → (size: md, rounded: true) — matches the goal-avatar
shape used elsewhere on the page.

Replace the hand-rolled <button> for Cancel/Back with DS::Button
variant: "ghost". Stepper now drills into the button's inner span to
swap the label, same pattern already used for the Continue/Create
button on the right.

Drop the now-unused footerLeftLabel target.

app/javascript/controllers/savings_goal_stepper_controller.js

@@ -15,6 +15,9 @@ export default class extends Controller {
     "step2Circle",
     "stepperLine",
     "modalSubtitle",
+    "nameInput",
+    "amountInput",
+    "avatarPreview",
     "linkedAccountCheckbox",
     "initialContributionAmount",
     "initialContributionAccountSelect",
@@ -23,7 +26,6 @@ export default class extends Controller {
     "reviewAccounts",
     "reviewSuggested",
     "footerLeftButton",
-    "footerLeftLabel",
     "footerRightButton",
     "submitButton",
   ];
@@ -91,6 +93,14 @@ export default class extends Controller {
     this.updateReview();
   }
 
+  nameChanged() {
+    if (!this.hasAvatarPreviewTarget || !this.hasNameInputTarget) return;
+    const name = this.nameInputTarget.value.trim();
+    const initial = name ? name.charAt(0).toUpperCase() : "?";
+    const inner = this.avatarPreviewTarget.querySelector('[data-testid="savings-goal-avatar"]');
+    if (inner) inner.textContent = initial;
+  }
+
   validateStep1() {
     const requiredInputs = this.step1PanelTarget.querySelectorAll(
       'input[name="savings_goal[name]"], input[name="savings_goal[target_amount]"]'
@@ -163,9 +173,12 @@ export default class extends Controller {
   }
 
   updateFooter() {
-    if (this.hasFooterLeftLabelTarget) {
-      this.footerLeftLabelTarget.textContent =
-        this.currentStep === 1 ? this.cancelLabelValue : this.backLabelValue;
+    if (this.hasFooterLeftButtonTarget) {
+      const labelSpan = this.footerLeftButtonTarget.querySelector("span");
+      if (labelSpan) {
+        labelSpan.textContent =
+          this.currentStep === 1 ? this.cancelLabelValue : this.backLabelValue;
+      }
     }
     if (this.hasFooterRightButtonTarget) {
       const labelSpan = this.footerRightButtonTarget.querySelector("span");

app/views/savings_goals/_form_stepper.html.erb

@@ -27,9 +27,9 @@
 
       <div>
         <label class="block text-sm font-medium text-primary mb-2"><%= t("savings_goals.form_stepper.step1.fields.name") %></label>
-        <div class="flex items-stretch gap-2">
-          <span class="shrink-0">
-            <%= render DS::FilledIcon.new(variant: :container, icon: "target", size: "lg", rounded: false) %>
+        <div class="flex items-center gap-2">
+          <span class="shrink-0" data-savings-goal-stepper-target="avatarPreview">
+            <%= render Savings::GoalAvatarComponent.new(name: savings_goal.name, color: savings_goal.color, size: "md") %>
           </span>
           <%= f.text_field :name,
                            placeholder: t("savings_goals.form_stepper.step1.fields.name_placeholder"),
@@ -160,13 +160,14 @@
     </section>
 
     <div class="flex items-center justify-between pt-2">
-      <button type="button"
-              class="text-sm font-medium text-secondary hover:text-primary px-2 py-2"
-              data-savings-goal-stepper-target="footerLeftButton"
-              data-action="click->savings-goal-stepper#footerLeft"
-              data-cancel-action="DS--dialog#close">
-        <span data-savings-goal-stepper-target="footerLeftLabel"><%= t("savings_goals.form_stepper.cancel") %></span>
-      </button>
+      <%= render DS::Button.new(
+        variant: "ghost",
+        text: t("savings_goals.form_stepper.cancel"),
+        data: {
+          savings_goal_stepper_target: "footerLeftButton",
+          action: "click->savings-goal-stepper#footerLeft"
+        }
+      ) %>
       <%= render DS::Button.new(
         text: t("savings_goals.form_stepper.continue"),
         variant: "primary",

app/views/savings_goals/new.html.erb

@@ -2,7 +2,7 @@
   <% dialog.with_header(custom_header: true) do %>
     <div class="flex items-start justify-between gap-3">
       <div class="flex items-start gap-3">
-        <%= render DS::FilledIcon.new(variant: :container, icon: "target", size: "lg", rounded: false) %>
+        <%= render DS::FilledIcon.new(variant: :container, icon: "target", size: "md", rounded: true) %>
         <div>
           <h2 class="text-base font-medium text-primary"><%= t(".heading") %></h2>
           <p class="text-sm text-secondary mt-0.5" data-savings-goal-stepper-modal-subtitle>