docs: correct the correction — absence of a .btn block does not imply the bump restyles

HistorianGateway has no local block AND no Bootstrap button call sites (all 15
buttons use the kit's .rail-btn chassis class), so the kit's .btn rule matches
nothing and bumping it changes nothing visible. My previous correction claimed the
opposite. Checking this needs two greps — declaration AND call sites — which come
apart exactly when an app doesn't use Bootstrap buttons.

ZB.MOM.WW.Theme/src/ZB.MOM.WW.Theme/wwwroot/css/layout.css

@@ -8,12 +8,22 @@
    OtOpcUa site.css, mxgw site.css and ScadaBridge — so it is upstreamed here in
    0.4.0 and those local copies can be trimmed on bump.
 
-   NOT universal, despite an earlier claim in this comment that listed all five:
-   HistorianGateway has NO local .btn sizing in either its committed tree or its
-   sweep branch — only vendored bootstrap.min.css. So on 0.3.1 its buttons render
-   at Bootstrap's default 1rem, and its bump to 0.4.0+ is a VISIBLE change (buttons
-   shrink to .85rem), not the no-op cleanup it is for the others. Do not assume a
-   consumer already has this sizing; check before calling a bump cosmetic.
+   NOT universal, despite an earlier claim here that listed all five. Checking
+   whether a consumer carries this block needs TWO questions, and they come apart:
+
+     (1) does it declare its own .btn sizing?   grep bs-btn-font-size (skip lib/bootstrap)
+     (2) does it USE Bootstrap buttons at all?  count call sites carrying a bare
+                                                `btn` token in class="…"
+
+   HistorianGateway answers no to BOTH: it styles all 15 of its buttons with the
+   side-rail chassis class .rail-btn, so it had no block to carry AND the kit's
+   .btn rule matches nothing there. Bumping it changes NOTHING visible — the rule
+   is inert until call sites are converted to Bootstrap.
+
+   Question (1) alone gives the wrong answer in both directions. "No local block"
+   read as "the kit now supplies sizing it lacked" produced a confident warning
+   that its buttons would shrink; they would not, because nothing matches. Ask (2)
+   before telling anyone a bump restyles their UI.
 
    Sized by CSS-variable override ONLY — never by redeclaring box properties.
    Bootstrap's .btn-group seam and radius machinery reads these same variables,