chore: bump version to v3.0.1

Updates version references in:
- README.md title
- CHANGELOG.md (new entry with all changes since v3.0.0)
- marketplace.json metadata
- CLAUDE.md project overview

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -6,7 +6,7 @@
   },
   "metadata": {
     "description": "Project management plugins with Gitea and NetBox integrations",
-    "version": "3.0.0"
+    "version": "3.0.1"
   },
   "plugins": [
     {