Improve UX of join requests and fix minor bugs (#492)

## Description of the implemented changes
The changes were:
- [x] Bugfixing
- [x] New Feature
- [ ] Breaking Change
- [ ] Refactoring

This PR improves the join-request flow and presentation quality, fixes several data-display issues in join/join-request screens, and adds a usability improvement in global settings (directly opening the join link). It also includes dependency updates and changelog maintenance.

## What has been changed?
- Join form (`JoinLive`) now renders inputs based on actual field types (including checkbox/date/number/email behavior instead of generic text-only handling).
- Join form custom-field labels are resolved from configured custom fields (fallback remains safe if lookup fails).
- Join-request details page (`JoinRequestLive.Show`) now:
  - resolves and shows custom field names instead of raw IDs,
  - formats boolean-like values (`on/true/1`, `off/false/0`) as localized `Yes/No`,
  - formats ISO date strings for better readability,
  - keeps legacy field handling while improving output consistency.
- Join-request detail layout was improved semantically and visually (`dl/dt/dd` structure for label/value rows).
- Global settings page now includes an **Open** button for the join URL (`target="_blank"`, `rel="noopener noreferrer"`, ARIA label).
- Added/updated tests around:
  - join field type rendering,
  - custom field labels in join-request views,
  - related auth/global-settings behavior.
- Updated translations (`default.pot`, `en`, `de`) for new UI strings.
- Updated dependencies/tooling (`mix.lock`, `mix.exs`, CI/renovate-related updates).
- Updated `CHANGELOG.md` entries for unreleased changes.

## Definition of Done
### Code Quality
- [x] No new technical depths
- [x] Linting passed
- [x] Documentation is added were needed

### Accessibility
- [x] New elements are properly defined with html-tags
- [x] Colour contrast follows WCAG criteria
- [x] Aria labels are added when needed
- [x] Everything is accessible by keyboard
- [x] Tab-Order is comprehensible
- [x] All interactive elements have a visible focus

### Testing
- [x] Tests for new code are written
- [ ] All tests pass
- [ ] axe-core dev tools show no critical or major issues

## Additional Notes
- Reviewer focus areas:
  - `lib/mv_web/live/join_live.ex`: input type derivation and custom field lookup strategy (`authorize?: false` read path used intentionally for field metadata).
  - `lib/mv_web/live/join_request_live/show.ex`: value-formatting logic (especially backward compatibility for legacy `form_data` payloads).
  - `lib/mv_web/live/global_settings_live.ex`: external-link behavior and accessibility attributes.
- The branch also contains dependency update commits; please review lockfile and CI-related changes separately from functional join/join-request changes.

Reviewed-on: #492
Co-authored-by: Simon <s.thiessen@local-it.org>
Co-committed-by: Simon <s.thiessen@local-it.org>

lib/mv_web/live/join_live.ex

@@ -5,7 +5,9 @@ defmodule MvWeb.JoinLive do
   """
   use MvWeb, :live_view
 
+  alias Ash.Resource.Info
   alias Mv.Membership
+  alias Mv.Membership.CustomFieldLookup
   alias MvWeb.JoinRateLimit
   alias MvWeb.Translations.MemberFields
 
@@ -54,10 +56,6 @@ defmodule MvWeb.JoinLive do
                 {gettext("Become a member")}
               </.header>
 
-              <p class="text-base-content/80">
-                {gettext("Please enter your details for the membership application here.")}
-              </p>
-
               <%= if @submitted do %>
                 <div data-testid="join-success-message" class="alert alert-success">
                   <p class="font-medium">
@@ -67,6 +65,9 @@ defmodule MvWeb.JoinLive do
                   </p>
                 </div>
               <% else %>
+                <p class="text-base-content/80">
+                  {gettext("Please enter your details for the membership application here.")}
+                </p>
                 <.form
                   for={@form}
                   id="join-form"
@@ -80,19 +81,41 @@ defmodule MvWeb.JoinLive do
                   <% end %>
 
                   <%= for field <- @join_fields do %>
-                    <div>
-                      <label for={"join-field-#{field.id}"} class="label">
-                        <span class="label-text">{field.label}{if field.required, do: " *"}</span>
+                    <%= if field.input_type == "checkbox" do %>
+                      <input type="hidden" name={field.id} value="off" />
+                      <label
+                        for={"join-field-#{field.id}"}
+                        class="label cursor-pointer justify-start gap-3"
+                      >
+                        <input
+                          type="checkbox"
+                          name={field.id}
+                          id={"join-field-#{field.id}"}
+                          checked={checkbox_checked?(@form.params[field.id])}
+                          required={field.required}
+                          class="checkbox checkbox-sm"
+                        />
+                        <span class="label-text">
+                          {field.label}<span :if={field.required} aria-hidden="true"> *</span>
+                        </span>
                       </label>
-                      <input
-                        type={input_type(field.id)}
-                        name={field.id}
-                        id={"join-field-#{field.id}"}
-                        value={@form.params[field.id]}
-                        required={field.required}
-                        class="input input-bordered w-full"
-                      />
-                    </div>
+                    <% else %>
+                      <div>
+                        <label for={"join-field-#{field.id}"} class="label">
+                          <span class="label-text">
+                            {field.label}<span :if={field.required} aria-hidden="true"> *</span>
+                          </span>
+                        </label>
+                        <input
+                          type={field.input_type}
+                          name={field.id}
+                          id={"join-field-#{field.id}"}
+                          value={@form.params[field.id]}
+                          required={field.required}
+                          class="input input-bordered w-full"
+                        />
+                      </div>
+                    <% end %>
                   <% end %>
 
                   <%!--
@@ -216,19 +239,32 @@ defmodule MvWeb.JoinLive do
 
   defp build_join_fields_with_labels(allowlist) do
     member_field_strings = Mv.Constants.member_fields() |> Enum.map(&Atom.to_string/1)
+    custom_field_by_id = custom_field_map(allowlist, member_field_strings)
 
     Enum.map(allowlist, fn %{id: id, required: required} ->
-      label =
-        if id in member_field_strings do
-          MemberFields.label(String.to_existing_atom(id))
-        else
-          gettext("Field")
-        end
-
-      %{id: id, label: label, required: required}
+      build_join_field(id, required, member_field_strings, custom_field_by_id)
     end)
   end
 
+  defp build_join_field(id, required, member_field_strings, custom_field_by_id) do
+    if id in member_field_strings do
+      label = MemberFields.label(String.to_existing_atom(id))
+      %{id: id, label: label, required: required, input_type: member_field_input_type(id)}
+    else
+      custom_field = Map.get(custom_field_by_id, id)
+      label = if custom_field, do: custom_field.name, else: gettext("Field")
+      input_type = custom_field_input_type(custom_field && custom_field.value_type)
+
+      %{id: id, label: label, required: required, input_type: input_type}
+    end
+  end
+
+  defp custom_field_map(allowlist, _member_field_strings) do
+    allowlist
+    |> Enum.map(& &1.id)
+    |> CustomFieldLookup.fetch_map_by_ids(authorize?: false, select: [:id, :name, :value_type])
+  end
+
   defp initial_form_params(join_fields) do
     join_fields
     |> Enum.map(fn f -> {f.id, ""} end)
@@ -236,8 +272,42 @@ defmodule MvWeb.JoinLive do
     |> Map.put(@honeypot_field, "")
   end
 
-  defp input_type("email"), do: "email"
-  defp input_type(_), do: "text"
+  defp member_field_input_type("email"), do: "email"
+
+  defp member_field_input_type(field_id) when is_binary(field_id) do
+    case member_field_atom(field_id) do
+      nil ->
+        "text"
+
+      field_atom ->
+        Mv.Membership.Member
+        |> Info.attribute(field_atom)
+        |> Map.get(:type)
+        |> input_type_for()
+    end
+  end
+
+  defp member_field_input_type(_), do: "text"
+
+  defp member_field_atom(field_id) when is_binary(field_id) do
+    Mv.Constants.member_fields()
+    |> Enum.find(&(Atom.to_string(&1) == field_id))
+  end
+
+  defp custom_field_input_type(type), do: input_type_for(type)
+
+  defp input_type_for(:date), do: "date"
+  defp input_type_for(Ash.Type.Date), do: "date"
+  defp input_type_for(:integer), do: "number"
+  defp input_type_for(Ash.Type.Integer), do: "number"
+  defp input_type_for(:boolean), do: "checkbox"
+  defp input_type_for(Ash.Type.Boolean), do: "checkbox"
+  defp input_type_for(:email), do: "email"
+  defp input_type_for(Mv.Membership.Email), do: "email"
+  defp input_type_for(_), do: "text"
+
+  defp checkbox_checked?(value) when value in [true, "true", "on", "1"], do: true
+  defp checkbox_checked?(_), do: false
 
   defp build_submit_attrs(params, join_fields) do
     allowlist_ids = MapSet.new(Enum.map(join_fields, & &1.id))
@@ -257,9 +327,12 @@ defmodule MvWeb.JoinLive do
       }
 
       form_data =
-        params
-        |> Enum.filter(fn {key, _} -> key in allowlist_ids and key not in typed end)
-        |> Map.new(fn {k, v} -> {k, String.trim(to_string(v))} end)
+        join_fields
+        |> Enum.filter(&(&1.id not in typed))
+        |> Map.new(fn field ->
+          {field.id, normalize_join_field_value(params[field.id], field.input_type)}
+        end)
+        |> Map.take(MapSet.to_list(allowlist_ids))
 
       attrs = %{attrs | form_data: form_data}
       {:ok, attrs}
@@ -271,6 +344,10 @@ defmodule MvWeb.JoinLive do
     if is_binary(v), do: String.trim(v), else: nil
   end
 
+  defp normalize_join_field_value(raw, _input_type) when is_binary(raw), do: String.trim(raw)
+  defp normalize_join_field_value(_raw, "checkbox"), do: "off"
+  defp normalize_join_field_value(_raw, _input_type), do: ""
+
   # Prefer X-Forwarded-For / X-Real-IP when behind a reverse proxy; fall back to peer_data.
   # Uses :inet.ntoa/1 for correct IPv4 and IPv6 string representation.
   defp client_ip_from_socket(socket) do