fix: correct version to 5.1.1 after patch release

- npm latest tag now correctly points to 5.1.0
- package.json updated to 5.1.1 (what patch should have made)
- installer version synced

package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "bmad-method",
-  "version": "5.0.1",
+  "version": "5.1.1",
   "description": "Breakthrough Method of Agile AI-driven Development",
   "keywords": [
     "agile",

tools/installer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "bmad-method",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "description": "BMad Method installer - AI-powered Agile development framework",
   "keywords": [
     "bmad",