Fix OpenCode interactive command to use --prompt flag

Author: Assistant

internal/agent/opencode.go

@@ -30,7 +30,7 @@ func (p *OpenCodeProvider) LoopCommand(ctx context.Context, prompt, workDir stri
 }
 
 func (p *OpenCodeProvider) InteractiveCommand(workDir, prompt string) *exec.Cmd {
-	cmd := exec.Command(p.cliPath)
+	cmd := exec.Command(p.cliPath, "--prompt", prompt)
 	cmd.Dir = workDir
 	return cmd
 }

internal/agent/opencode_test.go

@@ -86,6 +86,9 @@ func TestOpenCodeProvider_FixJSONCommand(t *testing.T) {
 	if outPath != "" {
 		t.Errorf("FixJSONCommand outPath = %q, want empty string", outPath)
 	}
+	if cmd.Path != "opencode" {
+		t.Errorf("FixJSONCommand Path = %q, want opencode", cmd.Path)
+	}
 }
 
 func TestOpenCodeProvider_InteractiveCommand(t *testing.T) {
@@ -94,6 +97,9 @@ func TestOpenCodeProvider_InteractiveCommand(t *testing.T) {
 	if cmd.Dir != "/work" {
 		t.Errorf("InteractiveCommand Dir = %q, want /work", cmd.Dir)
 	}
+	if len(cmd.Args) != 3 || cmd.Args[0] != "opencode" || cmd.Args[1] != "--prompt" || cmd.Args[2] != "my prompt" {
+		t.Errorf("InteractiveCommand Args = %v, want [opencode --prompt 'my prompt']", cmd.Args)
+	}
 }
 
 func TestOpenCodeProvider_ParseLine(t *testing.T) {