ai tags: default to showing only posts, not media assets.

Change the /ai_tags page to show only posts by default, not both posts
and unposted media assets mixed together. Showing media assets tended to
confuse users about why they couldn't add tags to these images. It also
distracted from the page's primary use case, which is gardening posts.

app/controllers/ai_tags_controller.rb

@@ -7,6 +7,7 @@ class AITagsController < ApplicationController
     limit = params[:limit].presence || CurrentUser.user.per_page
     @mode = params.fetch(:mode, "gallery")
     @preview_size = params[:size].presence || cookies[:post_preview_size].presence || MediaAssetGalleryComponent::DEFAULT_SIZE
+    params[:search][:is_posted] ||= "true" if request.format.html?
 
     @ai_tags = authorize AITag.visible(CurrentUser.user).paginated_search(params, limit: limit, count_pages: false)
     @ai_tags = @ai_tags.includes(:media_asset, :tag, :post) if request.format.html?

app/views/ai_tags/index.html.erb

@@ -14,7 +14,6 @@
     <% end %>
 
     <div class="border-b mb-4 flex flex-wrap gap-4">
-      <%= link_to "All", current_page_path(search: search_params.to_h.without("is_posted")), class: ["inline-block p-1 pb-2", (search_params[:is_posted].nil? ? "border-current border-b-2 -mb-px" : "inactive-link")] %>
       <%= link_to "Posted", current_page_path(search: search_params.merge(is_posted: true)), class: ["inline-block p-1 pb-2", (search_params[:is_posted].to_s.truthy? ? "border-current border-b-2 -mb-px" : "inactive-link")] %>
       <%= link_to "Unposted", current_page_path(search: search_params.merge(is_posted: false)), class: ["inline-block p-1 pb-2", (search_params[:is_posted].to_s.falsy? ? "border-current border-b-2 -mb-px" : "inactive-link")] %>
       <span class="flex-grow-1"></span>