fix(design): an audit of the S3d claims — the float shadow, filter hints, one action size per row (E28 S3d)

- A glass role's shadow is one token (shadow-float); the header search's drop-shadow utility had
  replaced its top highlight, and the debug pill's shadow-lg did the same. The surface-role lint
  rule now refuses a shadow size beside a role.
- Plex: every value that filters carries a hint (genre, certificate, studio had none), and the facts
  panel's year and certificate filter like the header's. filterKeyword -> filterValue.
- Downloads: the row resized its buttons with a [&_button] override that the save link escaped
  (28px beside 32px); the size is the primitive's md rung now.

frontend/src/components/PlexInfo.tsx

@@ -156,16 +156,42 @@ function FactsPanel({
   const tmdb = detail.tmdb;
   const studios = tmdb?.studios?.length ? tmdb.studios : detail.studio ? [detail.studio] : [];
   const rows: { key: string; label: string; node: ReactNode }[] = [];
-  if (detail.year != null)
-    rows.push({ key: "year", label: t("plex.info.facts.release"), node: detail.year });
+  // The same values filter here as in the header above (year, certificate, studios).
+  const year = detail.year;
+  if (year != null)
+    rows.push({
+      key: "year",
+      label: t("plex.info.facts.release"),
+      node: (
+        <Filterable
+          title={onFilter ? t("plex.info.filterYear", { year }) : undefined}
+          onClick={onFilter ? () => onFilter({ yearMin: year, yearMax: year }) : undefined}
+          className="hover:text-accent"
+        >
+          {year}
+        </Filterable>
+      ),
+    });
   if (detail.duration_seconds)
     rows.push({
       key: "runtime",
       label: t("plex.info.facts.runtime"),
       node: formatRuntime(detail.duration_seconds),
     });
-  if (detail.content_rating)
-    rows.push({ key: "cert", label: t("plex.info.facts.cert"), node: detail.content_rating });
+  const cert = detail.content_rating;
+  if (cert)
+    rows.push({
+      key: "cert",
+      label: t("plex.info.facts.cert"),
+      node: (
+        <Filterable
+          onClick={onFilter ? () => onFilter({ contentRatings: [cert] }) : undefined}
+          className="hover:text-accent"
+        >
+          {cert}
+        </Filterable>
+      ),
+    });
   if (tmdb?.budget)
     rows.push({ key: "budget", label: t("plex.info.facts.budget"), node: money(tmdb.budget) });
   if (tmdb?.revenue)
@@ -230,7 +256,6 @@ function KeywordsPanel({
           <Filterable
             key={k}
             tag
-            title={onFilter ? t("plex.info.filterKeyword", { name: k }) : undefined}
             onClick={onFilter ? () => onFilter({ keywords: [k] }) : undefined}
           >
             {k}