build: migrate from npm to pnpm with workspace catalogs

- Switch package manager to pnpm 10 via corepack
- Add pnpm-workspace.yaml with 54+ shared dependency catalogs
- Convert all workspace packages to catalog: and workspace:* protocols
- Upgrade Turborepo from 1.x to 2.8.12 (pipeline -> tasks)
- Upgrade apps/openpage-api from Next 15 to Next 16
- Update Docker, CI workflows, and GitHub Actions for pnpm
- Convert patch file to pnpm native format
- Replace deprecated next lint with standalone eslint
- Update all documentation references from npm to pnpm
- Fix stale dependabot config and documentation paths

.gitignore

@@ -20,9 +20,7 @@ build
 *.pem
 
 # debug
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
+pnpm-debug.log*
 
 # local env files
 .env