no-bug: Submit workspace creation form on Enter and cancel on Escape (gh-13549)

Co-authored-by: Zander Otavka <AlexanderOtavka@users.noreply.github.com>
Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>

src/zen/glance/zen-glance.css

@@ -83,6 +83,7 @@
       & label {
         max-width: 4rem;
         margin-left: 8px;
+        color: white;
       }
 
       & image {

src/zen/spaces/ZenSpaceCreation.mjs

@@ -148,6 +148,28 @@ class nsZenWorkspaceCreation extends MozXULElement {
       this.createButton.disabled = !this.inputName.value.trim();
     });
 
+    this.inputName.addEventListener("keydown", event => {
+      if (event.key === "Enter") {
+        event.preventDefault();
+        event.stopPropagation();
+        if (!this.createButton.disabled) {
+          this.createButton.doCommand();
+        }
+      }
+    });
+
+    // Bound on the root so Esc works regardless of which child has focus
+    // (name input, icon picker trigger, profile button, primary button).
+    // Open popups consume Esc before it reaches us, so the emoji/profile
+    // pickers still close as expected.
+    this.addEventListener("keydown", event => {
+      if (event.key === "Escape") {
+        event.preventDefault();
+        event.stopPropagation();
+        this.cancelButton.doCommand();
+      }
+    });
+
     this.inputIcon.addEventListener("command", this.onIconCommand.bind(this));
 
     this.profilesPopup = this.querySelector(