chore(go): audit providers copilot droid augment cline

Move the four providers onto managed_runtime.go and shell_command.go;
keep the Auggie wrappers, Cline metadata wrappers, and the Copilot and
Droid precondition handling provider-local.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

cmd/elydora/plugins/copilot_io.go

@@ -240,14 +240,7 @@ func writeCopilotChanges(
 	agentDirectory string,
 	preconditions []filePrecondition,
 ) error {
-	hasChanges := false
-	for _, change := range changes {
-		if change != nil {
-			hasChanges = true
-			break
-		}
-	}
-	if !hasChanges {
+	if !hasFileChanges(changes) {
 		return writeChanges(changes, label, rename, preconditions...)
 	}
 	if agentDirectory != "" {