feat(web): add JerapahFlow brand assets and apply them in the UI

Organize mark, wordmark, app icon, and YAML file icon under the theme brand folder.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/web/src/theme/brand.js

@@ -0,0 +1,13 @@
+import mark from "./brand/mark.png";
+import wordmark from "./brand/wordmark.png";
+import icon from "./brand/icon.png";
+import fileYaml from "./brand/file-yaml.png";
+
+/** Giraffe mark only. */
+export const brandMark = mark;
+/** Mark + JerapahFlow wordmark. */
+export const brandBanner = wordmark;
+/** App icon (giraffe + JF). */
+export const brandAppIcon = icon;
+/** Workflow YAML file icon. */
+export const brandWorkflowFile = fileYaml;