docs(prs): PR#23 names every test that verifies it (point 4)

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/prs/2026-09-04-PR#23-follow-up-builds.md

@@ -145,6 +145,8 @@ So that the invariant "nothing is scheduled during CLI runs or tests" holds: a C
 ##### Verified by
 
 - [FollowUpTriggerTest — "the trigger listens only while the watcher runs"](../../src/test/kotlin/de/hoennig/werkator/watcher/FollowUpTriggerTest.kt)
+- [WatcherTest — "start arms the follow-up trigger before the recovery, stop disarms it"](../../src/test/kotlin/de/hoennig/werkator/watcher/WatcherTest.kt)
+- [BuildCommandTest — "a green CLI build names the follow-up builds the server would run, and runs none"](../../src/test/kotlin/de/hoennig/werkator/commands/BuildCommandTest.kt)
 
 ## The Solution
 
@@ -179,7 +181,9 @@ Three places stay in sync with the new key, as the invariant demands: the data c
   Implemented: allowed, and the reference recommends a self-contained deployment command that rebuilds what it ships (Werkbaum's `deploy-prod.sh` does).
 - **A predecessor that exists only on a branch.**
   The host's `afterSuccessOf: frontend` refers to a name the branch layer may rename.
-  Implemented: refused at start for the primary configuration; for a branch whose layer lacks the name, a warning once per branch and commit, and no follow-up.
+  Implemented: refused at start for the primary configuration; for a branch whose layer lacks the name, a warning once per branch and commit, and no follow-up
+  (verified by [ConfigLoaderTest — "a branch whose layer lacks the predecessor loses only its follow-up"](../../src/test/kotlin/de/hoennig/werkator/config/ConfigLoaderTest.kt)).
+  An instance fragment checked by `init --apply` is not checked for its predecessor at all: the build it names may well live in the project config it is merged with, and the merged configuration is checked on every load anyway.
 
 ## Follow-up PRs