Split audits into Weigh Ins (bulk) and Bin Checks (discrete)

Replaces the unified audit system with two purpose-built flows:
- Weigh Ins: rebranded audit flow for bulk products (Flower, Concentrate,
  Tincture) with scale weigh, container weigh, and estimate modes
- Bin Checks: new bin-level presence check — select a bin, scan every item,
  resolve discrepancies (wrong bin, unknown, missing), auto-records presence
  audits on verified items

Adds cadence_days and last_checked to bins table, with per-bin overdue
tracking on the dashboard and bins view.

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

web/src/stats.ts

@@ -3,7 +3,7 @@
 // consumed. Gone items contribute spend but NOT grams (so daily averages
 // stay clean). Operates on the enriched Item[] view, not raw products.
 
-import type { Bootstrap, Item } from "./types.js";
+import type { Bin, Bootstrap, Item } from "./types.js";
 import { TYPES, helpers, enrichItems } from "./types.js";
 import { getToday, getStoredTimezone } from "./tz.js";
 
@@ -37,7 +37,8 @@ export interface Stats {
   goneCount: number;
   archivedCount: number;
   purchaseCount: number;
-  overdueAudits: Item[];
+  overdueWeighIns: Item[];
+  overdueBinChecks: Bin[];
   lowStockBulk: Item[];
   lowStockDiscreteGroups: {
     key: string;
@@ -220,7 +221,8 @@ export function computeStats(data: Bootstrap): Stats {
   }
   const avgGap = gaps.length > 0 ? gaps.reduce((a, b) => a + b, 0) / gaps.length : 0;
 
-  const overdueAudits = active.filter((p) => helpers.auditOverdue(p, todayStr));
+  const overdueWeighIns = active.filter((p) => helpers.auditOverdue(p, todayStr));
+  const overdueBinChecks = data.bins.filter((b) => helpers.binCheckOverdue(b, todayStr));
 
   const lowStockBulk = active.filter(
     (p) => p.kind === "bulk" && helpers.pctRemaining(p) < 0.25,
@@ -283,7 +285,8 @@ export function computeStats(data: Bootstrap): Stats {
     goneCount: gone.length,
     archivedCount: consumed.length + gone.length,
     purchaseCount: items.length,
-    overdueAudits,
+    overdueWeighIns,
+    overdueBinChecks,
     lowStockBulk,
     lowStockDiscreteGroups,
   };