docs: correct specificity arithmetic and spinner-clause accuracy in .dd-accent-icon comments

Glyph rule is (0,3,0) > (0,1,0) — beats .mud-secondary-text on specificity, not source order.
ReleaseHeroOverlay spinner comment now distinguishes dead glyph clauses from the live spinner clause that produced the intentional light delta.

DeepDrftPublic.Client/Controls/ReleaseHeroOverlay.razor.css

@@ -153,8 +153,11 @@
 
 /* The play/share glyphs are coloured by the shared .dd-accent-icon treatment (green-accent in
    both themes) applied on .release-hero-play / .release-hero-share in ReleaseHeroOverlay.razor —
-   see deepdrft-styles.css. No co-located colour rule here: a wrapper-level override could not
-   reach the .mud-secondary-text !important glyph anyway. */
+   see deepdrft-styles.css. No co-located colour rule here: the former white override was removed
+   because its glyph clauses (.mud-icon-button .mud-icon-root) could not reach the
+   .mud-secondary-text !important glyph at wrapper specificity, and its spinner clause
+   (.mud-progress-circular) was live but is now correctly covered by .dd-accent-icon —
+   making the spinner green-accent (was white) in light mode, the one intentional light delta. */
 
 @media (max-width: 599.98px) {
     .release-hero {