Move dt/sim_warp_factor from config.json to CLI flags

Both are run-mode knobs (how fast to drive this particular process),
not config.json material (a plant/hardware description that stays the
same regardless of how a run happens to be invoked) - --dt and
--sim-warp-factor, defaulting to 1.0 each (real time, 1-simulated-
second ticks) unless a dev/test run asks for a faster warp explicitly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019qvu5giu7gvRCyEWzf2Vpx

config.json.templ

@@ -1,8 +1,6 @@
 {
 	"ambient_temperature": 20,
 	"Controller" : {
-	"dt": 1,
-	"sim_warp_factor": 50.0,
 	"stirrer_name": "sim",
 	"plant_name": "sim",
 	"pid_type": "Smith"