fix(insights): drop the empty tail on the signal and narrative cards

Both overview cards carried a min-h floor sized for their tallest state and
applied it to every state, so the calm everyday read left a large empty band
at the bottom.

- Today's signal: the min-h-48 floor now applies only to the tall `fired`
  state; all-clear / watch / insufficient size to their short content.
- Period overview: the resolved card drops the min-h-40 floor and the footer's
  mt-auto that pinned the timestamp to the bottom of the floored height.

The in-flight skeletons keep their min-h footprint, so the first paint still
reserves the row and does not shift as the read resolves.

src/components/insights/coincident-deviation-card.tsx

@@ -81,8 +81,9 @@ function CoincidentProvenance({
 
 /**
  * The card shell — uppercase label + the provenance affordance, with the
- * state-specific body as children. Keeps every state on one card geometry so
- * the page reserves a stable footprint.
+ * state-specific body as children. The tall `fired` state keeps a `min-h` floor;
+ * the calmer everyday states size to their (short) content so the card carries
+ * no empty tail.
  */
 function CardShell({
   state,
@@ -99,13 +100,15 @@ function CardShell({
       data-slot="coincident-deviation-card"
       data-state={state}
       className={cn(
-        // `min-h` sized to the tallest realistic state (fired: 44px provenance
-        // header + the named-vitals body + the mandatory factors line). Every
-        // calmer state shares this footprint so the card — and everything below
-        // it on the overview — never shifts as the state resolves (the CLS the
-        // design pass closes). `min-h` not fixed `h`: a rare taller body still
-        // grows, it just never shrinks below the reserved height.
-        "bg-card flex min-h-48 w-full min-w-0 flex-col gap-2 rounded-xl border p-4 md:p-6",
+        "bg-card flex w-full min-w-0 flex-col gap-2 rounded-xl border p-4 md:p-6",
+        // `min-h` floor only on the tallest state (fired: 44px provenance header
+        // + the named-vitals body + the mandatory factors line). The calmer
+        // everyday states (all-clear / watch / insufficient) carry a single
+        // short body, so flooring them to the fired height left a large empty
+        // tail; they now size to their content. The in-flight `CardSkeleton`
+        // keeps the `min-h-48` footprint so the initial paint still reserves the
+        // row and does not shift as the read resolves.
+        state === "fired" && "min-h-48",
         // At most amber — never destructive/red. The fired state borders
         // warning; every calmer state keeps the neutral card border.
         state === "fired" ? "border-warning/40" : "border-border",

src/components/insights/period-narrative-card.tsx

@@ -22,10 +22,10 @@ import {
  * fresh one out of band, so this card never blocks on the provider.
  *
  * Restraint guarantees: plain React text children (NO markdown — the whole
- * tree forbids a markdown library for XSS reasons), no score, no chart, a
- * single ⓘ provenance disclosure, and a fixed `min-h` footprint shared across
- * the loading / preparing / resolved states so the card — and everything below
- * it on the overview — never shifts (no CLS).
+ * tree forbids a markdown library for XSS reasons), no score, no chart, and a
+ * single ⓘ provenance disclosure. The in-flight skeleton reserves a `min-h`
+ * footprint so the first paint holds the row open (CLS-safe); the resolved card
+ * then sizes to its content so a short narrative leaves no empty tail.
  */
 
 type NarrativePeriod = "week" | "month";
@@ -98,7 +98,12 @@ function ProvenanceDisclosure({
 }
 
 const SHELL =
-  "bg-card border-border flex min-h-40 w-full min-w-0 flex-col gap-3 rounded-xl border p-4 md:p-6";
+  "bg-card border-border flex w-full min-w-0 flex-col gap-3 rounded-xl border p-4 md:p-6";
+// The in-flight skeleton keeps a `min-h` floor so the initial paint reserves the
+// row (CLS-safe). The resolved card drops the floor and sizes to its content —
+// a short narrative used to leave a large empty tail under the prose, widened by
+// the footer's `mt-auto` pinning it to the bottom of the floored height.
+const SKELETON_SHELL = `${SHELL} min-h-40`;
 
 export function PeriodNarrativeCard({
   enabled = true,
@@ -123,7 +128,7 @@ export function PeriodNarrativeCard({
       <div
         data-slot="period-narrative-card-skeleton"
         aria-hidden="true"
-        className={cn(SHELL, className)}
+        className={cn(SKELETON_SHELL, className)}
       >
         <div className="flex h-7 items-center justify-between gap-2">
           <div className="bg-muted/40 h-3 w-32 rounded" />
@@ -199,7 +204,7 @@ export function PeriodNarrativeCard({
       )}
 
       {narrative ? (
-        <p className="text-muted-foreground mt-auto text-[11px]">
+        <p className="text-muted-foreground text-[11px]">
           {data?.revalidating
             ? t("insights.narrativeUpdating")
             : t("insights.narrativeUpdated", {