chore: streamline compatibility tracking and documentation

CONTRIBUTING.md

@@ -40,7 +40,7 @@ Documentation updates, preview screenshots, installation guides, and translation
 
 ## Development Setup
 
-- **Go 1.21+** for template rendering and the CLI tool
+- **Go 1.21+** for template rendering and the CLI tool; Go modules download `github.com/urfave/cli/v2` and its dependencies
 
 ### Previewing Locally (Static)
 
@@ -56,7 +56,7 @@ cd tools && go run . dev
 ```
 
 - Watches `themes/**/*.tmpl` — auto-rebuilds on save
-- Pure Go HTTP server with SSE push — no external dependencies
+- HTTP server and SSE live reload use Go's standard library; the CLI has a Go module dependency
 - Re-renders templates in-process and pushes reload events to the browser
 - Terminal output: `themes/aurora/mail/repo/release.tmpl changed` → `[Builder] Rebuild done in 45ms`