Fix back navigation from activity page to cards (#2727)

Three changes needed to support navigating back from a card to the
activity page:

- Add root_path to the prefer_referrer allowlist on the card show page
- Switch event links from HTML target="_top" to data-turbo-frame="_top"
  so Turbo handles the navigation and turbo:before-visit fires to save
  the referrer
- Normalize trailing slashes in the referrer path comparison so
  /account_id and /account_id/ both match

ref: https://app.fizzy.do/5986089/cards/2390

app/javascript/controllers/turbo_navigation_controller.js

@@ -24,8 +24,9 @@ export default class extends Controller {
   referrerBackLinkTargetConnected(link) {
     if (!this.#referrerUrl || !this.#referrerLabel) { return }
 
-    const allowedPaths = (link.dataset.turboNavigationAllowedReferrerPaths || "").split(",")
-    const referrerPath = new URL(this.#referrerUrl).pathname
+    const stripTrailingSlash = path => path.replace(/\/$/, "")
+    const allowedPaths = (link.dataset.turboNavigationAllowedReferrerPaths || "").split(",").map(stripTrailingSlash)
+    const referrerPath = stripTrailingSlash(new URL(this.#referrerUrl).pathname)
     if (!allowedPaths.includes(referrerPath)) { return }
 
     link.href = this.#referrerUrl

app/views/cards/show.html.erb

@@ -7,7 +7,7 @@
 
 <% content_for :header do %>
   <div class="header__actions header__actions--start">
-    <%= link_back_to_board @card.board, prefer_referrer: [ cards_path, board_path(@card.board) ] %>
+    <%= link_back_to_board @card.board, prefer_referrer: [ root_path, cards_path, board_path(@card.board) ] %>
   </div>
 <% end %>
 

app/views/events/event/_layout.html.erb

@@ -2,8 +2,8 @@
       id: dom_id(event, "timelined"),
       class: "event event--#{ event.action } #{ "golden-effect" if event.card.golden? } center-block flex flex-column full-width align-start justify-start position-relative",
       style: "--card-color: #{ card.closed? ? "var(--color-card-complete)" : card.color };",
-      target: "_top",
       data: {
+        turbo_frame: "_top",
         related_element_target: "related",
         related_element_group_value: card.id,
         action: "mouseover->related-element#highlight mouseout->related-element#unhighlight" } do %>