refactor: simplify shell behavior for exec commands

- Remove interactive prompt setup for CMD and PowerShell when using exec commands.
- Update CMD to use `/c` instead of `/k` for proper shell exit after exec commands.
- Adjust PowerShell arguments to omit `-NoExit` for seamless shell termination post-execution.
- Refactor script generation to streamline flow and exit behavior.

fix: prevent prompt activity corruption during inactivity timeout

- Stop activity monitor immediately upon detecting terminal inactivity to lock the last activity frame.
- Ensure prompt isn't incorrectly recorded during the EndBuffer wait period.

Author: phil-scott-78

src/VcrSharp.Infrastructure/Processes/TtydProcess.cs

@@ -104,18 +104,20 @@ public async Task StartAsync()
             args.Add(_shellCommand[0]); // Shell executable (e.g., "bash", "pwsh", "cmd")
 
             // PowerShell: use script file to avoid command line length limits
+            // Don't use -NoExit when we have Exec commands - shell should exit after commands complete
             if (shellName is "pwsh" or "powershell")
             {
                 args.Add("-NoLogo");
                 args.Add("-NoProfile");
-                args.Add("-NoExit");
                 _startupScriptPath = CreateStartupScriptFile(script, shellName);
                 args.Add("-File");
                 args.Add(_startupScriptPath);
             }
             else
             {
-                args.Add(_shellConfig.ExecutionFlag); // Shell-specific flag (-c, /k)
+                // For CMD, use /c (run and exit) instead of /k (run and remain) with Exec commands
+                var execFlag = (shellName is "cmd" or "cmd.exe") ? "/c" : _shellConfig.ExecutionFlag;
+                args.Add(execFlag);
                 args.Add(script);
             }
         }
@@ -244,28 +246,11 @@ private string BuildStartupScript()
         // Generate shell-specific sleep command
         var sleepCommand = GetShellSpecificSleepCommand(_execStartDelay.TotalSeconds);
 
-        // Build the full script: sleep → prompt setup → exec commands
-        // Exec commands must be LAST as they are the content being recorded
+        // Build the full script: sleep → exec commands
+        // Shell exits after commands complete (no return to interactive mode)
         var script = sleepCommand;
 
-        // Add prompt setup BEFORE exec commands
-        if (!string.IsNullOrEmpty(_shellConfig.InteractiveReturnCommand))
-        {
-            script += $"{separator}{_shellConfig.InteractiveReturnCommand}";
-        }
-        else if (isCmd)
-        {
-            // CMD with /k stays interactive but needs prompt setup
-            script += $"{separator}prompt $G$S";
-        }
-        else if (isPowerShell)
-        {
-            // PowerShell with -NoExit stays interactive, add prompt function
-            script += $"{separator}Set-PSReadLineOption -HistorySaveStyle SaveNothing -PredictionSource None";
-            script += $"{separator}function prompt {{ '> ' }}";
-        }
-
-        // Exec commands run LAST (the content being recorded)
+        // Exec commands run and then shell exits
         script += $"{separator}{commandChain}";
 
         return script;

src/VcrSharp.Infrastructure/Session/VcrSession.cs

@@ -451,9 +451,16 @@ private async Task WaitForInactivityAsync(CancellationToken cancellationToken)
                 if (inactiveDuration >= inactivityTimeout)
                 {
                     // Terminal has been inactive long enough
-                    VcrLogger.Logger.Debug("Terminal inactive for {InactiveDuration}s, waiting end buffer",
+                    VcrLogger.Logger.Debug("Terminal inactive for {InactiveDuration}s, stopping activity monitor before end buffer",
                         inactiveDuration.TotalSeconds);
 
+                    // Stop activity monitor NOW to lock in the last activity frame
+                    // This prevents the prompt from being counted as activity during EndBuffer wait
+                    if (_activityMonitor != null)
+                    {
+                        await _activityMonitor.StopAsync();
+                    }
+
                     // Wait end buffer to capture final frames
                     await Task.Delay(_options.EndBuffer, cancellationToken);
                     break;