instructions: chains of packages - stack-dev writes ## Kette, stack-close names the next link (#205)

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

Co-Authored-By: Claude Code <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

instructions/dev/issue-tracking.md

@@ -27,6 +27,7 @@ issues at that URL, which is exactly why `dist export` excludes
 - [Steps](#steps)
 - [Incoming stubs](#incoming-stubs)
 - [Ready to build](#ready-to-build)
+- [Chains](#chains)
 - [Renames and other decay in the tracker](#renames-and-other-decay-in-the-tracker)
 - [Citing an issue in the repo](#citing-an-issue-in-the-repo)
 - [What no tool checks](#what-no-tool-checks)
@@ -50,6 +51,8 @@ issues at that URL, which is exactly why `dist export` excludes
   ready (§ Ready to build).
 - Prioritising: deciding what to pick up next, or re-labelling after the ground
   moved.
+- A design session yields several packages with an order, or inserts, removes or moves
+  one in an existing sequence: write or repair the `## Kette` sections (§ Chains).
 - Closing one: the body is rewritten to its final state first, and only then
   closed (step 7).
 - A rename or move ships: sweep the open issues for text that assumed the old
@@ -208,7 +211,7 @@ issues at that URL, which is exactly why `dist export` excludes
 
    | `status/` | Means |
    |---|---|
-   | `status/blocked` | Waiting on another, still-open issue - not workable on its own, whatever its `prio/` says. Name the blocking issue in the body. |
+   | `status/blocked` | Waiting on another, still-open issue - not workable on its own, whatever its `prio/` says. Name the blocking issue in the body. A place in a chain (§ Chains) is an order, not a block. |
    | `status/unconfirmed` | A reported suspicion, not yet checked against actual behaviour. Applies to any `kind/`, not just `kind/defect`. |
    | `status/incoming` | A human's stub: a request or a thought, filed at whatever length it arrived, deliberately short of everything step 1 asks for. **Never implemented as it stands** - § Incoming stubs. |
 
@@ -337,6 +340,40 @@ session fills on its own is the same gap a `status/incoming` stub leaves (§ Inc
 only better disguised. The useful side effect of the cut between the two phases is that it
 tests this definition - if a cold session cannot build from the body, it was not ready.
 
+## Chains
+
+Packages that are meant to be built one after another lose the thread when each is closed:
+which issue comes next is, at best, written in a body nobody reads after closing. A package that
+is part of an ordered sequence therefore ends its body with a section of this exact form, as the
+**last** section:
+
+```
+## Kette
+
+Kette „<name>“
+- Vorgänger: #A        (or: keiner - erstes Glied)
+- Nachfolger: #C       (or: keiner - letztes Glied)
+```
+
+The heading and the line openings are quoted vocabulary and stay German, like the bodies they
+sit in. Three rules keep it cheap and checkable:
+
+- **Neighbours only, never a list of all links.** Inserting, removing or moving a package then
+  touches the two bodies beside it, not every body in the chain. The whole sequence is
+  recovered by walking `Nachfolger` links from the first link.
+- **The two neighbours point at each other.** If #B names #A as `Vorgänger`, #A names #B as
+  `Nachfolger`. A one-sided pointer is the defect; `stack-dev` checks every link it touched
+  before ending its phase.
+- **Order is a planning decision, not a dependency.** A real dependency still carries
+  `status/blocked` (step 5) and names the blocker in the body. A chain position alone never
+  blocks anything.
+
+`stack-dev` writes the section and keeps the neighbours in step (its steps 3 and 5);
+`stack-close` reads it after closing and names the next link (its step 5), and lifts
+`status/blocked` from the successor when the closed package was that body's only open blocker,
+with the comment step 6 asks for. The successor is *ready* when it carries `kind/build` and
+neither `status/incoming` nor `status/unconfirmed`; otherwise the next phase for it is design.
+
 ## Renames and other decay in the tracker
 
 A rename is not finished when the tree is green. Renaming a package, a path,