chore(agent-roles-catalog): merge copy-editor into proofreader, refresh editorial roles

Merge the copy-editor (📐) and proofreader (🧹 "Корректор") editorial roles
into a single role. Keep slug `proofreader`, drop slug `copy-editor`, and set
the merged role's emoji to 📐.

- index.json: remove copy-editor; bump structural-editor, line-editor,
  fact-checker, proofreader to version 2 (narrator unchanged); update editorial
  bundle description (ru/en).
- bundles/editorial/{ru,en}.json: delete copy-editor; refresh emoji/name/
  description/instructions of structural-editor, line-editor, fact-checker and
  the merged proofreader verbatim from gitmost-agenty-ru.md / gitmost-agents-en.md;
  preserve autoStart and launchMessage; leave narrator untouched.
- README.md: drop copy-editor from the editorial role list.

Validated with scripts/check.mjs (OK).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent-roles-catalog/README.md

@@ -23,7 +23,7 @@ agent-roles-catalog/
 Currently shipped bundles:
 
 - `editorial` — the editorial suite (structural-editor, line-editor,
-  copy-editor, fact-checker, proofreader, narrator), languages `ru`, `en`.
+  fact-checker, proofreader, narrator), languages `ru`, `en`.
 - `research` — a single `researcher` role, languages `ru`, `en`.
 
 ## How it's served