fix(backend): redact MCP secrets at interactive-runner log site, clean orphan config

- The interactive runner logged req.Command verbatim on every passthrough
  start/restart/resume, re-leaking the Codex MCP -c env/header tokens that the
  manager log sites redacted. Add a LogCommand field (redacted) and log it.
- writeFileNoFollow now removes the empty/partial file on write or close failure
  so a later SkipIfExists probe doesn't skip writing the real config.

Author: carlosflorencio

apps/backend/internal/agent/runtime/lifecycle/manager_passthrough.go

@@ -450,9 +450,13 @@ func (m *Manager) writeFileNoFollow(path string, content []byte) (bool, error) {
 	}
 	if _, werr := file.Write(content); werr != nil {
 		_ = file.Close()
+		// Remove the empty file so a later SkipIfExists probe doesn't see it and
+		// silently skip writing the real config.
+		_ = os.Remove(path)
 		return false, fmt.Errorf("write passthrough MCP config: %w", werr)
 	}
 	if cerr := file.Close(); cerr != nil {
+		_ = os.Remove(path)
 		return false, fmt.Errorf("close passthrough MCP config: %w", cerr)
 	}
 	return true, nil
@@ -640,8 +644,11 @@ func (m *Manager) profileCLIFlagTokens(p *AgentProfileInfo) []string {
 // terminal WebSocket is already connected).
 func buildInteractiveStartRequest(sessionID string, execution *AgentExecution, pt agents.PassthroughConfig, env map[string]string, cmd agents.Command, immediateStart bool) process.InteractiveStartRequest {
 	return process.InteractiveStartRequest{
-		SessionID:       sessionID,
-		Command:         cmd.Args(),
+		SessionID: sessionID,
+		Command:   cmd.Args(),
+		// Redacted copy logged in place of Command by the interactive runner so
+		// Codex MCP `-c` overrides (env/headers tokens) never reach process logs.
+		LogCommand:      redactPassthroughArgs(cmd.Args()),
 		WorkingDir:      execution.WorkspacePath,
 		Env:             env,
 		PromptPattern:   pt.PromptPattern,

apps/backend/internal/agentctl/server/process/interactive_lifecycle.go

@@ -153,7 +153,7 @@ func (r *InteractiveRunner) Start(ctx context.Context, req InteractiveStartReque
 		r.logger.Info("interactive process created (waiting for terminal dimensions)",
 			zap.String("process_id", id),
 			zap.String("session_id", req.SessionID),
-			zap.Strings("command", req.Command),
+			zap.Strings("command", req.commandForLog()),
 			zap.String("working_dir", req.WorkingDir),
 		)
 	}
@@ -208,7 +208,7 @@ func (r *InteractiveRunner) immediateStartProcess(req InteractiveStartRequest, p
 	r.logger.Info("interactive process started immediately",
 		zap.String("process_id", id),
 		zap.String("session_id", req.SessionID),
-		zap.Strings("command", req.Command),
+		zap.Strings("command", req.commandForLog()),
 		zap.String("working_dir", req.WorkingDir),
 	)
 	return nil

apps/backend/internal/agentctl/server/process/interactive_runner.go

@@ -22,6 +22,7 @@ import (
 type InteractiveStartRequest struct {
 	SessionID            string            `json:"session_id"`                       // Required: Agent session owning this process
 	Command              []string          `json:"command"`                          // Required: Command and args to execute
+	LogCommand           []string          `json:"log_command,omitempty"`            // Optional: redacted copy of Command for logging (e.g. MCP `-c` overrides with tokens); falls back to Command when unset
 	WorkingDir           string            `json:"working_dir"`                      // Working directory
 	Env                  map[string]string `json:"env,omitempty"`                    // Additional environment variables
 	PromptPattern        string            `json:"prompt_pattern,omitempty"`         // Regex pattern to detect agent prompt for turn completion
@@ -38,6 +39,15 @@ type InteractiveStartRequest struct {
 	IsUserShell          bool              `json:"is_user_shell,omitempty"`          // Mark as user shell process (excluded from session-level lookups)
 }
 
+// commandForLog returns the command to log: the redacted LogCommand when the
+// caller supplied one, otherwise the raw Command.
+func (r InteractiveStartRequest) commandForLog() []string {
+	if len(r.LogCommand) > 0 {
+		return r.LogCommand
+	}
+	return r.Command
+}
+
 // InteractiveProcessInfo represents the state of an interactive process.
 type InteractiveProcessInfo struct {
 	ID         string               `json:"id"`