Revert "Fix Assist to use mailbox system instead of direct 'in' file writes"

This reverts commit bdd0039eba.

cmd/Assist/main.go

@@ -3,7 +3,6 @@ package main
 
 import (
 	"anvillm/internal/sandbox"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"log"
@@ -355,42 +354,6 @@ func sendPrompt(id, prompt string) error {
 	if !isConnected() {
 		return fmt.Errorf("not connected to anvilsrv")
 	}
-	
-	// Create message JSON
-	msg := map[string]interface{}{
-		"to":      id,
-		"type":    "PROMPT",
-		"subject": "User prompt",
-		"body":    prompt,
-	}
-	msgJSON, err := json.Marshal(msg)
-	if err != nil {
-		return fmt.Errorf("failed to marshal message: %w", err)
-	}
-	
-	// Write to user outbox
-	timestamp := time.Now().Unix()
-	filename := fmt.Sprintf("msg-%d.json", timestamp)
-	path := filepath.Join("user/outbox", filename)
-	
-	fid, err := fs.Create(path, plan9.OWRITE, 0644)
-	if err != nil {
-		return fmt.Errorf("failed to create message file: %w", err)
-	}
-	defer fid.Close()
-	
-	_, err = fid.Write(msgJSON)
-	if err != nil {
-		return fmt.Errorf("failed to write message: %w", err)
-	}
-	
-	return nil
-}
-
-func sendPromptDirect(id, prompt string) error {
-	if !isConnected() {
-		return fmt.Errorf("not connected to anvilsrv")
-	}
 	path := filepath.Join(id, "in")
 	fid, err := fs.Open(path, plan9.OWRITE)
 	if err != nil {
@@ -607,15 +570,8 @@ func handlePromptWindow(w *acme.Win, sess *SessionInfo) {
 			}
 			prompt := strings.TrimSpace(string(body))
 			if prompt != "" {
-				var sendErr error
-				if cmd == "Prompt" {
-					sendErr = sendPromptDirect(sess.ID, prompt)
-				} else {
-					sendErr = sendPrompt(sess.ID, prompt)
-				}
-				if sendErr != nil {
-					fmt.Fprintf(os.Stderr, "Failed to send %s: %v\n", strings.ToLower(cmd), sendErr)
-					continue
+				if err := sendPrompt(sess.ID, prompt); err != nil {
+					fmt.Fprintf(os.Stderr, "Failed to send prompt: %v\n", err)
 				}
 				w.Ctl("delete")
 				return