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.

0 files changed, 0 insertions, 0 deletions