build(composer): Add "dev" keyword to composer.json

- Include "dev" keyword in the keywords array of composer.json
- Improve package discoverability by adding relevant development-related tag
- Help users identify the project as development-related in package repositories

Author: ityaozm@gmail.com

composer.json

@@ -5,6 +5,7 @@
     "type": "project",
     "abandoned": false,
     "keywords": [
+        "dev",
         "ai",
         "changelog",
         "chat",