feat show measurement age on index quick cards

Display the time since last reading (e.g. '2m ago') alongside the value and unit on the compact probe cards.

Commit
af28ce9c3aa4e998b0c1dd86fea6d2aae2be1816
Author
GPT-5 medium <codex@openai.com>
Author date
Committer
GPT-5 medium <codex@openai.com>
Committer date
roles/dashboard/public/js/dashboard/quick-readings.js
index 2a0e98b3..1b4c9f0a 100644..100644
@@ -106,7 +106,7 @@
106 106 meter.setAttribute("aria-valuenow", Math.round(percent).toString());
107 107 meter.setAttribute("aria-label", `${label} ${qualityLabel(quality)} at ${formatValue(value, range)} ${unit}`);
108 108 item.querySelector("[data-reading-quick-value]").textContent = Number.isFinite(value)
109 Removed: ? `${formatValue(value, range)} ${unit}`
109 Added: ? `${formatValue(value, range)} ${unit} · ${age}`
110 110 : "—";
111 111 }
112 112