refactor: rename module to pipely and migrate web UI to MUI

- Rename Go module from onixbyte.com/message-converter-manifest to onixbyte.com/pipely
- Replace shadcn UI with Material UI components across all pages
- Add axios-based API client in shared/web-client with credentials management
- Organise API calls into feature modules: auth, devices, deployments, artefacts, users
- Add .env.example with VITE_API_BASE_URL pointing to pipely.onixbyte.com
- Fix deprecated FormEvent → MouseEvent in dialog submit handlers

web/.gitignore

@@ -12,6 +12,12 @@ dist
 dist-ssr
 *.local
 
+# Environment variables
+.env
+.env.local
+.env.*.local
+!.env.example
+
 # Editor directories and files
 .vscode/*
 !.vscode/extensions.json