powershell, 79 bytes

Result

AC

Duration

2833ms

Code [DL]

$t,$s=$input|%{$_.TrimEnd()}
"$t
"*$s.Length+$s[-1].PadRight($t.Length,75)|echo

stdin

                                             T    
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
     K                                            

stdout

                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
                                             T
     KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe1308a540 /* 6 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x55902f09ec10 /* 6 vars */ <unfinished ...>
13    execve("/usr/bin/pwsh", ["/usr/bin/pwsh", "/volume/CODE"], 0x55902f09ec28 /* 6 vars */ <unfinished ...>
12    <... execve resumed> )            = 0
13    <... execve resumed> )            = 0
12    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
16    +++ exited with 0 +++
17    +++ exited with 0 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
31    +++ exited with 0 +++
30    +++ exited with 0 +++
29    +++ exited with 0 +++
28    +++ exited with 0 +++
27    +++ exited with 0 +++
26    +++ exited with 0 +++
25    +++ exited with 0 +++
24    +++ exited with 0 +++
23    +++ exited with 0 +++
22    +++ exited with 0 +++
21    +++ exited with 0 +++
20    +++ exited with 0 +++
19    +++ exited with 0 +++
18    +++ exited with 0 +++
15    +++ exited with 0 +++
14    +++ exited with 0 +++
13    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=62, si_stime=24} ---
11    +++ exited with 0 +++