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/stack-close/SKILL.md

@@ -103,6 +103,31 @@ always will.
 4. **Comment, then close.** The closing comment carries the one changelog line
    `instructions/dev/issue-tracking.md` step 3 asks for. Then close the issue.
 
+5. **Name the next link of the chain, if there is one.** Read the closed body's `## Kette` section
+   (`instructions/dev/issue-tracking.md` § Chains) and follow its `Nachfolger` line:
+
+   - **Successor open:** if its body names the issue just closed as its only open blocker, take
+     `status/blocked` off it and say so in a comment there (issue-tracking.md step 6); with
+     another open blocker the label stays. Then give the line below.
+   - **Successor already closed:** keep following `Nachfolger` links to the first open link and
+     name that one.
+   - **No open link left (`Nachfolger: keiner`, or only closed links):** give the last line below.
+   - **No `## Kette` section:** give no line, as before.
+
+   Close the phase with exactly one of these fixed lines, in the instance's KB language per
+   `AGENTS.md` § File naming. A link is *ready* when it carries `kind/build` and neither
+   `status/incoming` nor `status/unconfirmed`:
+
+   > #N is closed. Next in the chain "<name>": #M - `/stack-build #M`, here or after `/clear`.
+
+   > #N is closed. Next in the chain "<name>": #M - `/stack-dev #M`, here or after `/clear`.
+
+   > Chain "<name>" is complete.
+
+   The first is for a ready link, the second for one that is not and needs design first. **Do
+   not run the named skill yourself** - the line only tells the operator what comes next, the
+   same rule as at every other phase end (`instructions/dev/stack-mode.md` § The three phases).
+
 ## Decision points
 
 - **The work package spans several sessions?** Run this skill once, at the point the package is
@@ -112,6 +137,9 @@ always will.
   it "correctly."
 - **Nothing to close - the session's own exploration, no publish happened?** This skill does not
   apply; there is no package to close.
+- **The chain section points at a successor that does not point back, or at an issue that does
+  not exist?** Say so in the closing line's place instead of guessing a successor, and leave the
+  repair to `/stack-dev` (`issue-tracking.md` § Chains).
 
 ## Scope