Add erfa/chaostreff node-kind creation conventions

lib/ccc_conventions.rb: NODE_KINDS registry replaces the kind-specific
branches previously scattered across nodes_controller#create (tags),
unique_path-position check). Each kind declares its parent lookup
(a Proc - Update's "update"/"press_release" continue to genuinely
find-or-create their year-folder via Update.find_or_create_parent;
erfa/chaostreff use a plain find_by_unique_name!, since their parent
nodes are fixed and a missing one should fail loudly, not be silently
created), its tags, and (new) its default template.

Node gains a default_template_name column (migration, with backfill
for existing update-tree nodes via node.update? - reusing that method
rather than re-deriving its unique_path check in raw SQL). Page#set_template
now inherits from node.default_template_name, falling back to the old
update?-based check only when the column is blank, and only fills in
template_name when nothing's already been explicitly chosen - a
deliberate change from the previous behavior, which unconditionally
overwrote template_name on every save regardless of manual selection.
Node#update? itself is unchanged and still used as-is by
admin_controller's sitemap filtering - a genuinely different, still
valid use of that check.

"generic" stays special-cased in the controller, parametrized by
params[:parent_id] at request time - doesn't fit "kind implies a fixed
lookup" and isn't in the registry.

nodes#new's four hardcoded radio buttons and nodes_controller's
kind-specific case/when branches are both replaced by iterating/looking
up this one registry - adding a new kind now means one new hash entry,
not four scattered edits.

3 files changed, 26 insertions, 18 deletions

diff --git a/app/controllers/nodes_controller.rb b/app/controllers/nodes_controller.rb
index 494887d..1e1def2 100644
--- a/app/controllers/nodes_controller.rb
+++ b/app/controllers/nodes_controller.rb
@@ -33,17 +33,17 @@ class NodesController < ApplicationController
     
     @node = Node.new
     @node.parent_id = find_parent
-    @node.slug = params[:title].parameterize.to_s
-   
+    @node.slug = slug_for(params[:title])
+
+    config = CccConventions::NODE_KINDS[params[:kind]]
+
     if @node.save
       @node.draft.update(:title => params[:title])
-      case params[:kind]
-        when "update"
-          @node.draft.tag_list.add("update")
-        when "press_release"
-          @node.draft.tag_list.add("update", "pressemitteilung")
-      end
+      Array(config && config[:tags]).each { |t| @node.draft.tag_list.add(t) }
       @node.draft.save!
+
+      @node.update!(default_template_name: config[:template]) if config && config[:template]
+
       redirect_to(edit_node_path(@node))
     else
       render :new
@@ -103,9 +103,17 @@ class NodesController < ApplicationController
     
     redirect_to node_path(@node)
   end
-  
+
+  def parameterize_preview
+    render plain: slug_for(params[:title])
+  end
+
   private
 
+    def slug_for(title)
+      title.to_s.parameterize
+    end
+
     def node_params
       params.fetch(:node, {}).permit(:slug, :parent_id, :staged_slug, :staged_parent_id)
     end
@@ -120,18 +128,15 @@ class NodesController < ApplicationController
     
     def find_parent
       case params[:kind]
-      when "top_level"
-        Node.root.id
-      when "update"
-        Update.find_or_create_parent.id
-      when "press_release"
-        Update.find_or_create_parent.id
       when "generic"
         if params[:parent_id] && Node.find(params[:parent_id])
           params[:parent_id]
         else
           nil
         end
+      else
+        config = CccConventions::NODE_KINDS[params[:kind]]
+        config && config[:parent] ? config[:parent].call.id : nil
       end
     end
 end
diff --git a/app/models/page.rb b/app/models/page.rb
index c982c2e..20461bf 100644
--- a/app/models/page.rb
+++ b/app/models/page.rb
@@ -225,9 +225,8 @@ class Page < ApplicationRecord
     end
 
     def set_template
-      if node && node.update?
-        self.template_name = "update"
-      end
+      return if template_name.present?
+      self.template_name = node&.default_template_name || (node&.update? ? "update" : nil)
     end
 
     def rewrite_links_in_body
diff --git a/config/routes.rb b/config/routes.rb
index a7775b3..cf4733c 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -31,6 +31,10 @@ Cccms::Application.routes.draw do
     end
 
     resources :nodes do
+      collection do
+        get :parameterize_preview
+      end
+
       member do
         put :unlock
         put :publish