Squashed commit of the following:

commit 75d7f1d
Author: Alan Guo Xiang Tan <gxtan1990@gmail.com>
Date:   Mon Jan 19 13:45:11 2026 +0800

    DEV: Add backward compatibility for tag object arrays (discourse#47)

    What is the problem?

    Discourse core PR #36678 changes `renderTag` to pass tag objects
    instead of strings to custom tag renderers. This breaks the
    `iconTagRenderer` function which expects the `tag` parameter to be
    a string and calls `escapeExpression(tag)` directly.

    What is the solution?

    Extract the tag name at the start of `iconTagRenderer` using
    `typeof tag === "string" ? tag : tag.name` before processing.
    Also rename the local `tagName` variable to `htmlTagName` to avoid
    confusion with the extracted tag name. This ensures backward
    compatibility with both the old string format and the new object format.

Author: gormus

spec/system/page_objects/components/tag_icon.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module PageObjects
+  module Components
+    class TagIcon < PageObjects::Components::Base
+      def has_icon_for_tag?(tag_name:, icon:, color: nil)
+        selector = ".discourse-tag[data-tag-name='#{tag_name}'] .tag-icon"
+        selector += "[style*='color: #{color}']" if color
+        selector += " .d-icon-#{icon}"
+        page.has_css?(selector)
+      end
+
+      def has_no_icon_for_tag?(tag_name:)
+        page.has_css?(".discourse-tag[data-tag-name='#{tag_name}']") &&
+          page.has_no_css?(".discourse-tag[data-tag-name='#{tag_name}'] .tag-icon")
+      end
+    end
+  end
+end

spec/system/tag_icons_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require_relative "page_objects/components/tag_icon"
+
+RSpec.describe "Tag icons", type: :system do
+  fab!(:tag) { Fabricate(:tag, name: "support") }
+  fab!(:topic) { Fabricate(:topic, tags: [tag]) }
+  fab!(:post) { Fabricate(:post, topic:) }
+  fab!(:user)
+
+  let(:topic_page) { PageObjects::Pages::Topic.new }
+  let(:tag_icon) { PageObjects::Components::TagIcon.new }
+  let!(:theme) { upload_theme_component }
+
+  before do
+    SiteSetting.tagging_enabled = true
+    theme.update_setting(:tag_icon_list, "support,question-circle,#ff0000")
+    theme.save!
+    sign_in(user)
+  end
+
+  it "displays tag with icon on topic page" do
+    topic_page.visit_topic(topic)
+    expect(tag_icon).to have_icon_for_tag(tag_name: "support", icon: "question-circle", color: "#ff0000")
+  end
+
+  it "displays tag without icon when not configured" do
+    theme.update_setting(:tag_icon_list, "")
+    theme.save!
+
+    topic_page.visit_topic(topic)
+    expect(tag_icon).to have_no_icon_for_tag(tag_name: "support")
+  end
+end