workflow: drop docs/WhatsNew.md (Notify carries done-state on its own)

WhatsNew.md duplicated the Notify text into a file the only reader
(the user) does not consult. Removed the file and trimmed every
reference in the live control docs (CLAUDE.md, skills/boss,
skills/implement). The editorial rules (no internals,
telegram-pragmatic, factual) are preserved in skills/boss as
notify-text discipline. Historical specs/plans/journals are not
rewritten — they show the contemporaneous state.

skills/implement/SKILL.md

@@ -140,10 +140,8 @@ unstaged changes. Nothing is committed yet.
 5. Append one line to `docs/journals/INDEX.md` and include it in
    the same commit (or a follow-up commit):
    `- YYYY-MM-DD — iter <iter_id>: <one-line title> → <YYYY-MM-DD>-iter-<iter_id>.md`
-6. If trigger is done-state and the user is away, write a
-   `docs/WhatsNew.md` entry + run `notify.sh` per
-   `skills/boss/SKILL.md` "Done-state notifications: WhatsNew.md"
-   subsection.
+6. If trigger is done-state and the user is away, run `notify.sh`
+   per `skills/boss/SKILL.md` "Done-state notifications" subsection.
 
 ### Step 4 — Boss handling (on BLOCKED)