refactor!: rename module to github.com/theirongolddev/cburn

Change module path from 'cburn' to 'github.com/theirongolddev/cburn'
to enable standard Go remote installation:

  go install github.com/theirongolddev/cburn@latest

This is a BREAKING CHANGE for any external code importing this module
(though as a CLI tool, this is unlikely to affect anyone).

All internal imports updated to use the new module path.

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

cmd/config_cmd.go

@@ -4,7 +4,7 @@ package cmd
 import (
 	"fmt"
 
-	"cburn/internal/config"
+	"github.com/theirongolddev/cburn/internal/config"
 
 	"github.com/spf13/cobra"
 )