refactor(setup): consolidate prettier config and streamline CI

- Replace scattered .prettierignore files with a single root config
- Add scripts/ci.js to orchestrate lint, format, typecheck, commitlint, and build
- Simplify ci.yml to use ci.js and npm ci
- Apply prettier formatting to docs, locales, and HTML files

docs/developer-guide.md

@@ -24,7 +24,7 @@ For contribution rules and expectations, see [../CONTRIBUTING.md](../CONTRIBUTIN
 
 ## 📦 Project Structure
 
-This is a **monorepo** with npm workspaces. 
+This is a **monorepo** with npm workspaces.
 
 Published packages: