refactor(admin): the console speaks the Settings vocabulary without an accent

Twenty-six of twenty-eight admin files already used the Settings card and
header. What made the console read as its own system was everything on top of
that: three hand-rolled cards, a header slot that meant five different things,
and a heading the frame took but never painted.

- `SectionFrame` drops `title` and `subtitle`. Seventeen call sites passed
  both into a component that has rendered neither since v1.18.6.1 — the shell
  reads the same keys itself. A prop contract nothing honours is a promise the
  next reader believes.
- The invite card, the four host-metric headers, and the `/admin` welcome
  card stop hand-rolling `bg-card border rounded-xl` shells with their own
  padding steps and their own heading weights. `text-sm` as a card title on
  the first card of a page, directly above a correct one, was the first thing
  the eye landed on.
- The header status slot carries status. The backups run, the invite create,
  the danger-zone wipe, and the user filters come out of it; the app-log
  refresh stays but reads as the secondary it is.
- Loading states paint their card and header. Encryption returned a bare
  spinner row and then a card, so the section jumped when the status landed —
  the fix `coach-feedback-section.tsx` already carried, applied where it was
  missing. Same for the notification-status card.
- One label/value tile. `StatusItem`, the encryption section's private `Stat`,
  the user-management inline panels and the backups upload box were four
  fills and three paddings for one role.
- The overview stopped printing the running version, build SHA and build time
  twice, thirty pixels apart. The version tile owns build identity — it is the
  one that checks for a newer release; the snapshot owns what is running.
- `ai-server-key` had three paragraphs stacked in a muted `text-xs` slot;
  one sentence stays there and the two that carry information move into the
  body as foreground. The central-codex consent copy moves the same way, and
  its disconnect is `variant="destructive"` — which `ConfirmButton` refused to
  accept, so every destructive confirm in the tree had been hand-tinting an
  outline instead.
- Leftovers: the `-mt-2` correcting the card's own rhythm, two alpha hovers on
  text, `text-[10px]` badges, the redundant `space-y-6` wrapper, the empty
  state repeating the header's CTA, and the `mt-6` a card added inside a
  frame that already spaces its children.

src/components/admin/central-codex-section.tsx

@@ -21,6 +21,8 @@ import { Loader2, ShieldAlert, Sparkles, Trash2 } from "lucide-react";
 import { toast } from "sonner";
 
 import { Badge } from "@/components/ui/badge";
+import { SettingsInfoTile } from "@/components/settings/_info-tile";
+import { SettingsCardActions } from "@/components/settings/_card-actions";
 import { Button } from "@/components/ui/button";
 import { ConfirmButton } from "@/components/ui/confirm-button";
 import { SettingsCard } from "@/components/settings/settings-card";
@@ -167,10 +169,9 @@ export function CentralCodexSection() {
       />
 
       <div className="space-y-4">
-        <div className="text-muted-foreground flex items-start gap-2 text-xs">
-          <ShieldAlert className="mt-0.5 size-3.5 shrink-0" aria-hidden />
-          <p className="min-w-0">{t("admin.centralCodex.honesty")}</p>
-        </div>
+        <SettingsInfoTile icon={ShieldAlert} tone="warning">
+          <p className="text-foreground">{t("admin.centralCodex.honesty")}</p>
+        </SettingsInfoTile>
 
         {data?.connectedAt && isConnected && (
           <p className="text-muted-foreground text-xs">
@@ -181,25 +182,27 @@ export function CentralCodexSection() {
         )}
 
         {isConnected ? (
-          <ConfirmButton
-            slot="admin-central-codex-disconnect"
-            variant="outline"
-            size="sm"
-            className="text-destructive min-h-11 shrink-0 sm:min-h-9"
-            icon={<Trash2 className="h-4 w-4" />}
-            label={t("admin.centralCodex.disconnectButton")}
-            title={t("admin.centralCodex.disconnectTitle")}
-            body={t("admin.centralCodex.disconnectBody")}
-            confirmLabel={t("admin.centralCodex.disconnectConfirm")}
-            pending={disconnecting}
-            onConfirm={handleDisconnect}
-          />
+          <SettingsCardActions>
+            <ConfirmButton
+              slot="admin-central-codex-disconnect"
+              variant="destructive"
+              size="sm"
+              className="min-h-11 shrink-0 sm:min-h-9"
+              icon={<Trash2 className="h-4 w-4" />}
+              label={t("admin.centralCodex.disconnectButton")}
+              title={t("admin.centralCodex.disconnectTitle")}
+              body={t("admin.centralCodex.disconnectBody")}
+              confirmLabel={t("admin.centralCodex.disconnectConfirm")}
+              pending={disconnecting}
+              onConfirm={handleDisconnect}
+            />
+          </SettingsCardActions>
         ) : deviceCode ? (
           <div className="border-primary bg-primary/5 space-y-3 rounded-lg border-l-4 p-4">
             <p className="text-sm font-medium">
               {t("settings.ai.deviceCodeHeading")}
             </p>
-            <ol className="text-muted-foreground list-decimal space-y-2 pl-5 text-sm">
+            <ol className="text-muted-foreground list-decimal space-y-2 pl-6 text-sm">
               <li>
                 {t("settings.ai.deviceCodeStep1")}{" "}
                 <a
@@ -248,20 +251,22 @@ export function CentralCodexSection() {
             </div>
           </div>
         ) : (
-          <Button
-            variant="outline"
-            onClick={handleConnect}
-            disabled={devicePolling}
-            className="min-h-11 w-full sm:min-h-9 sm:w-auto"
-            data-slot="admin-central-codex-connect"
-          >
-            {devicePolling ? (
-              <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-            ) : (
-              <Sparkles className="h-4 w-4" />
-            )}
-            {t("admin.centralCodex.connectButton")}
-          </Button>
+          <SettingsCardActions>
+            <Button
+              size="sm"
+              onClick={handleConnect}
+              disabled={devicePolling}
+              className="min-h-11 w-full sm:min-h-9 sm:w-auto"
+              data-slot="admin-central-codex-connect"
+            >
+              {devicePolling ? (
+                <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+              ) : (
+                <Sparkles className="h-4 w-4" />
+              )}
+              {t("admin.centralCodex.connectButton")}
+            </Button>
+          </SettingsCardActions>
         )}
       </div>
     </SettingsCard>