feat(ttl): Run the CPU stress as a systemd unit, and add two config knobs

mlucas-avx2 was backgrounded with '&' in the login shell, so it belonged
to that one terminal. Close Tera Term, drop the console, or reconnect on
a different session and the load was gone - and 'jobs' from the new
session showed nothing to say so. A multi-day soak could spend most of
its length with an idle CPU while the thermal numbers looked fine.

Script B now starts it as a transient unit:

  systemd-run --unit=mlucas-amm --property=Type=exec \
    --property=Restart=always --property=RestartSec=2 ...

The log is truncated once with '>' before the unit starts and appended
with '>>' inside it, so a restart adds to the run instead of erasing it.
'systemctl is-active mlucas-amm' now sits beside 'jobs', both in the
one-shot check and in every pass of the monitor loop. The old '&' line is
kept commented out above the new one to fall back to.

Script C has the matching stop. utils/kill_all_process.ttl is only
"kill $(jobs -p)" and a systemd unit is not a shell job, so without this
the load would have run through the post-test snapshot and into the next
test - every temperature and power reading taken at full load, with
nothing in 'show interfaces status' to reveal it. mlucas_amm_log is
copied to /host/hw-eval/jobs/ with the other stress logs.

Two values move into config.ttl:

  EN_timestamp      feeds logopen's 5th argument in Script A, so the
                    per-line timestamp is a knob rather than a literal 1
  BMC_USB_RUNTIME   feeds Script B's ping unit; it was hard-coded to
                    -w 14400 (4 h), which no longer matched the soak
                    lengths the SSD and USB knobs were being set to

SSD_RUNTIME and USB_RUNTIME also go 600 -> 3600, so the shipped default
is a one hour stress rather than the ten minutes V1.1.7 went out with.
--runtime is still the job's overall limit; COUNT does not multiply it.

Script A's Version History carries the V1.1.8 entries for all of this.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014RetWKFZFG1ZHcitQAyhwM

src/Script_ABC_Blanton/config.ttl

@@ -6,6 +6,7 @@ strTestcase="ENV"      ;ENV,EMC,Margin...etc
 
 EN_Margin         = 0  ; 1: Enable Margin Test, 0: Disable Margin Test
 EN_log            = 1  ; 1: Enable log, 0: Disable log
+EN_timestamp      = 1  ; 1: Enable timestamp in log, 0: Disable timestamp in log
 
 ;================================================================
 ; FAN_SPEED
@@ -20,10 +21,11 @@ SWB_UNIT1         = 1   ; 1 = this DUT has switch unit 1, wait for it ; 0 = skip
 ;================================================================
 ; Stress_Test
 ;================================================================
-SSD_RUNTIME = 600       ; Unit seconds, 600 = 10 minutes
-SSD_COUNT   = 720       ; Total time = SSD_RUNTIME * SSD_COUNT
-USB_RUNTIME = 600       ; Unit seconds, 600 = 10 minutes
-USB_COUNT   = 720       ; Total time = USB_RUNTIME * USB_COUNT
+SSD_RUNTIME = 3600          ; Unit seconds, 3600 = 1 hour
+SSD_COUNT   = 240           ; Total time = SSD_RUNTIME * SSD_COUNT
+USB_RUNTIME = 3600          ; Unit seconds, 3600 = 1 hour
+USB_COUNT   = 240           ; Total time = USB_RUNTIME * USB_COUNT
+BMC_USB_RUNTIME = 172800    ; Unit seconds, 172800 = 2 days
 
 ;================================================================
 ; Prompt Definitions