fix: credential get fallback, update type field, and code refinements (v2.47.1) (#703)

- GET /credentials/:id is not in the n8n public API; fall back to
  list + filter, catching both 403 and 405 responses
- Forward optional `type` field in credential update for n8n versions
  that require it in PATCH payload
- Strip `data` field from create/update credential responses
- Code simplification: typed error handling, consolidated booleans,
  null-coalescing in version fetch

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.47.0",
+  "version": "2.47.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",