feat: rename repository name from chatgpt-on-wechat to CowAgent

- Update GitHub URLs in README.md (badges, release links, clone address, wiki, issues, contributors)
- Add project rename notice with SEO keywords and git remote update command
- Update docs/docs.json GitHub links
- Update all docs (zh/en/ja) across guide, intro, models, releases, skills
- Update run.sh and scripts/run.ps1 clone URLs and directory names
- Docker image name (zhayujie/chatgpt-on-wechat) kept unchanged for compatibility

docs/docs.json

@@ -24,13 +24,13 @@
       },
       {
         "label": "GitHub",
-        "href": "https://github.com/zhayujie/chatgpt-on-wechat"
+        "href": "https://github.com/zhayujie/CowAgent"
       }
     ]
   },
   "footer": {
     "socials": {
-      "github": "https://github.com/zhayujie/chatgpt-on-wechat"
+      "github": "https://github.com/zhayujie/CowAgent"
     }
   },
   "navigation": {