Drop the work log from TODO.md; keep only open work (closes #255)

TODO.md held a dated log of finished steps, merge history and accounts
of earlier live-feed runs. It now holds the Status line, the open Next
Step and an empty Future Steps. The Workflow section deletes the
finished Next Step instead of moving it to Completed Steps. README
"TODO" no longer says the file lists the steps done.

Model: opus-5-5

README.md

@@ -1100,8 +1100,7 @@ calls one of them. The scripts:
 
 ## TODO
 
-`TODO.md` holds the working list: the next step, the steps done and the steps
-planned.
+`TODO.md` holds the working list: the next step and the steps planned.
 
 ## License