dashy-soc-board: add the expanded Vault panel screenshot

Step 5 re-audit - real screenshot of the Vault tile's expanded detail
panel (UNSEALED, real lease/token/KV/secret-engine counts, TTL
distribution, CA cert expiry), showing the specialty-widget behavior
the Layout section describes but the existing screenshot doesn't show.
Captured after fixing the metrics-reader token issue found while
requesting this screenshot - first attempt genuinely showed a false
SEALED state, now shows the real healthy panel.

docs/dashy-soc-board.md

@@ -59,6 +59,10 @@ This is the real board, not a mockup of the layout — the dependency ladder, th
 
 ![The real SOC Board: a 6-tier dependency ladder and fleet-wide Wazuh KPIs on top, an Active Issues strip below that, then a grid of per-host tiles with severity badges and 24h error sparklines](../assets/dashy-soc-board.png)
 
+Clicking through to one of those "folded-in specialty widgets" — the Vault seal-state panel, expanded on the secrets host's own tile:
+
+![The Vault tile expanded: UNSEALED banner, active lease/token/KV-secret/secret-engine counts, token TTL distribution, and PKI CA cert expiry for both mounts, alongside that host's own Wazuh findings by category](../assets/dashy-soc-board-vault-panel.png)
+
 > [!TIP]
 > **Deliberately scoped**: security/error/warning signal only. Per-app uptime is handled separately by Dashy's own native status checks on individual tiles — the only up/down signal inside this board is *infrastructure-tier* reachability from Prometheus, not per-app availability. Keeping the scope narrow — resisting the temptation to also make this the uptime dashboard — is what keeps the board actually scannable instead of turning into a second copy of Grafana.