feat(types): ship ten editorial diagram types in one release (#118)

Adds ten editorial diagram types with light, dark, and full-editorial examples; updates the taxonomy, gallery, descriptions, references, and synchronized plugin version; and adds maintainer/visual-proof contribution gates.

Co-authored-by: Jacopo Vendramin <vendraminjacopo@gmail.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,6 +2,22 @@
 
 <!-- One or two sentences: what changed and why. -->
 
+## Visual proof
+
+<!--
+Required when this PR adds or changes a diagram, example, or template.
+Attach rendered screenshots—not source snippets—for every changed variant. A new
+diagram type must show its light, dark, and full editorial examples. Use a small
+captioned table or contact sheet so reviewers can compare the whole set at a glance.
+Write "Not applicable" only when the PR has no visual output changes.
+-->
+
+| Variant | Rendered preview |
+|---|---|
+| Light | |
+| Dark | |
+| Full editorial | |
+
 ## Validation gates
 
 <!-- Mark what you ran and that it passed. CI runs all of these on the PR too. -->
@@ -19,8 +35,9 @@
 - [ ] No new entries added to `scripts/lint-skin-baseline.txt`
 - [ ] Generated and source files are consistent (extractor ↔ verifier ↔ reference ↔ command)
 - [ ] Accessible SVG contract satisfied for new/changed examples
+- [ ] Rendered screenshots are attached for every new/changed diagram variant, or visual proof is marked not applicable
 - [ ] Code of Conduct respected
 
 ## Related issues
 
-<!-- Link any issues this closes, e.g. "Closes #12". -->
+<!-- Link any issues this closes, e.g. "Closes #12". -->