stack: Upgrade-Pfad bekommt eine eigene manual-Instruktion, INSTALL.md verweist darauf (#108)

Files changed:
- CHANGES.md
- INSTALL.md
- VERSION
- instructions/session-setup.md
- instructions/upgrade-instance.md
- tools/CONTRACT.md
- tools/chemenu/commands/dist_cmd.py
- tools/chemenu/tests/test_dist_upgrade.py

tools/chemenu/commands/dist_cmd.py

@@ -1045,8 +1045,13 @@ def run_upgrade(
         summary += (
             f" {len(migration_chain)} migration(s) now outstanding - run `wikitool migrate status`."
         )
+    # One pointer rather than a second copy of the order: the steps after the
+    # swap live in instructions/upgrade-instance.md, which ships with every
+    # instance. Naming the resume *command* rather than a step number keeps this
+    # line correct when that file's numbering moves.
     summary += (
-        " Nothing was committed. Now run, in order: `wikitool instructions sync`, `doctor`, "
-        "`docs verify`, `instructions verify`, `lint` - then restart the agent session."
+        " Nothing was committed and nothing is verified yet."
+        " `instructions/upgrade-instance.md` carries the order for everything that follows"
+        " and resumes at `wikitool instructions sync`."
     )
     success(summary)

tools/chemenu/tests/test_dist_upgrade.py

@@ -192,6 +192,24 @@ def test_unchanged_and_new_files_are_written_silently(instance, tmp_path):
     assert stamp["files"]["types/entity.md"] == _digest("new\n")
 
 
+def test_closing_report_points_at_the_upgrade_instruction(instance, tmp_path, capsys):
+    """Everything after the swap has exactly one written order, and it is not
+    this line: the report names the instruction that carries it and the command
+    the run resumes at, rather than a second copy of the list that drifts
+    (AGENTS.md invariant 8). A run that reads only this output must still be
+    able to find the rest."""
+    release = _release(
+        tmp_path, "release", "1.1.0",
+        {"AGENTS.md": "core\n", "tools/wikitool": "#!/bin/sh\n"},
+    )
+
+    dist_cmd.run_upgrade(release)
+
+    out = " ".join(capsys.readouterr().out.split())  # rich wraps; rejoin first
+    assert "instructions/upgrade-instance.md" in out
+    assert "instructions sync" in out
+
+
 @pytest.mark.parametrize("preserved", [".wikitool-kb.json", "CHANGES.md", "kb/log.md", "raw/notes/.gitkeep"])
 def test_seeded_once_paths_are_never_written_even_if_the_release_stamp_lists_them(
     instance, tmp_path, preserved