Features: the deferred key set proves its own reporting coverage (fleetd #337)

11-Features.md

@@ -4281,3 +4281,31 @@ Measured on merge: replacing the `.filter(...::add)` with one that logs every na
 left all 1358 tests green — the noise control was correct and nothing held it there. Two tests now
 cover both duties, including the **reverse** policy order (allow-list first, then deny-by-default),
 because a guard fixed in one direction is not automatically fixed in the other.
+
+---
+
+## The deferred key set now proves its own reporting coverage too
+
+**What it does.** `ConfigRefTopLevelReportingCoverageTest` covered `COLD_KEYS` and `SPLIT_KEYS` only.
+It now covers the deferred bucket as well. The deferred set moved out of the test and into
+`ConfigRef.DEFERRED_KEYS` (package-private, 11 keys), and `changedDeferredKeys` became
+package-private like `changedColdKeys` and `changedSplitKeys`, so the test calls the real method
+instead of a copy of the list. A name in any of the three sets with no comparison behind it now
+fails the build, by name.
+
+**On.** Always on — a unit test (fleetd #337).
+
+**Why it exists.** The deferred bucket is the largest of the four: 11 of the 22 top-level keys. It
+was also the one bucket where a name could be added with no code behind it and every checker stayed
+green. Measured before the fix: dropping `guard`'s comparison out of `changedDeferredKeys` while
+`"guard"` stayed in the set left all 1355 tests green. An operator who changes such a key gets no
+"restart needed" line, so the daemon keeps running config that matches no file on disk and says
+nothing.
+
+**One thing to know for maintenance.** The real number of uncovered keys was **6 of 11** — `guard`,
+`worktreeRoot`, `spawnReadyTimeoutMs`, `spawnReadyPollMs`, `quarantineCooldownSeconds` and
+`leadHeartbeat`. My own ticket listed a different six. The worker re-derived the list by mutating
+each key one at a time, as the brief asked, and contradicted me on two entries: `lifecycle` was
+already covered, and `worktreeRoot` was uncovered and missing from my list. Both corrections were
+checked again on merge with a third mutation. **A list in a ticket is a starting point, not a
+measurement** — re-derive it, and say so when it disagrees.