docs: Issue-Body ist das Plan-File - fortlaufend aktuell, Abschluss ist die letzte Aktualisierung (4.1.2, #44)

Files changed:
- CHANGES.md
- VERSION
- instructions/dev/issue-tracking.md
- instructions/dev/stack-dev/SKILL.md

instructions/dev/stack-dev/SKILL.md

@@ -43,9 +43,11 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    engineering, memory and deploy-time learning; consult before a design decision in those
    areas.
    [issue-tracking.md](../issue-tracking.md) - open work lives in Gitea issues, one per work
-   package, labelled `area/`, `kind/`, `prio/` and `size/`, with the body kept as the current
-   truth rather than as a first post. There is no `TODO.md`. Read it before filing something
-   for later, before editing an issue, or before deciding what to pick up next.
+   package, labelled `area/`, `kind/`, `prio/` and `size/`. There is no `TODO.md`. **The body
+   of the issue you are working on is this session's plan file:** keep it current as the state
+   moves, not at the end, so an interrupted session leaves a body the next one can resume from.
+   Read it before filing something for later, before editing or closing an issue, or before
+   deciding what to pick up next.
    [testing-conventions.md](../testing-conventions.md) - the suite runs against a deliberately
    empty machine; what the autouse fixture already neutralizes, and what a test still has to
    establish itself. Read it before adding or changing a test.