Add erfa/chaostreff node-kind creation conventions, part 2

The following changes were already announced in the last commit, but
the files forgotten. Here's them actually attached.

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.

New read-only admin/conventions view dumps the NODE_KINDS registry as
a reference table for whoever's confused later about how a given kind
behaves - deliberately just renders the same label/hint text used on
nodes#new rather than re-describing parent/tags/template separately,
since decomposing the parent Proc would mean either invoking it
(Update's has a real side effect - creates the year folder) or
re-stating its logic a second time in a different shape, either of
which risks drifting from the actual behavior.

1 files changed, 11 insertions, 0 deletions

diff --git a/app/views/admin/conventions.html.erb b/app/views/admin/conventions.html.erb
new file mode 100644
index 0000000..72f6214
--- /dev/null
+++ b/app/views/admin/conventions.html.erb
@@ -0,0 +1,11 @@
+<h1>Node creation conventions</h1>
+
+<table id="conventions">
+  <tr><th>Kind</th><th>What happens</th></tr>
+  <% @node_kinds.each do |kind, config| %>
+    <tr>
+      <td><%= kind %></td>
+      <td><%= resolve_kind_text(config[:label]) %> — <%= resolve_kind_text(config[:hint]) %></td>
+    </tr>
+  <% end %>
+</table>