Fix floating point display in audit history and estimated remaining

Round bulk audit values to 2 decimal places in the audit history list
and the linear-decay subtitle. Remove container weight / tare from the
detail rows — the info is internal to the audit flow and showing the
stale initial value after audits is confusing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/ProductDetail.tsx

@@ -67,12 +67,6 @@ export function ProductDetail({
       : []),
     ["Purchase date", fmt.date(item.purchaseDate, getStoredTimezone())],
     ["Bin", isCheckedOut ? "In your custody" : bin ? bin.name : <span style={{ color: "var(--ink-3)" }}>—</span>],
-    ...(item.containerWeight != null
-      ? [
-          ["Container weight", `${item.containerWeight.toFixed(2)}g`] as [string, React.ReactNode],
-          ["Tare (empty jar)", `${(item.containerWeight - item.weight).toFixed(2)}g`] as [string, React.ReactNode],
-        ]
-      : []),
     ["Audit cadence", `Every ${cfg?.cadenceDays ?? "—"} days · ${cfg?.auditMode ?? "—"}`],
     [
       "Cost per gram",
@@ -296,7 +290,7 @@ export function ProductDetail({
                     fontStyle: "italic",
                   }}
                 >
-                  Estimated by linear decay since last {last.mode} on {fmt.dateShort(last.date, getStoredTimezone())} ({last.value}
+                  Estimated by linear decay since last {last.mode} on {fmt.dateShort(last.date, getStoredTimezone())} ({last.value.toFixed(2)}
                   {cfg?.unit}). Re-audit to update.
                 </div>
               )}
@@ -393,10 +387,10 @@ export function ProductDetail({
                     </div>
                     <div className="mono" style={{ fontSize: 13, textAlign: "right" }}>
                       <div>
-                        {a.value} {cfg?.unit}
+                        {item.kind === "discrete" ? a.value : a.value.toFixed(2)} {cfg?.unit}
                       </div>
                       <div style={{ fontSize: 10, color: "var(--ink-3)" }}>
-                        was {a.prev} {cfg?.unit}
+                        was {a.prev != null ? (item.kind === "discrete" ? a.prev : a.prev.toFixed(2)) : "—"} {cfg?.unit}
                       </div>
                     </div>
                   </div>