Add trial-balance (GL health) indicator to Chart of Accounts

Surfaces the audit #2 check in the UI: a badge at the top of the Chart of
Accounts page shows "Trial balance: Balanced" or "off by $X (excess
debits/credits)". Computed in AccountsController.Index from already-loaded
accounts: debit-normal (Asset/COGS/Expense) minus credit-normal
(Liability/Equity/Revenue) CurrentBalance, which nets to ~0 for balanced
books. Helps companies spot one-sided postings / opening-balance gaps.

Help KB + Settings article updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/PowderCoating.Web/Controllers/AccountsController.cs

@@ -69,6 +69,14 @@ public class AccountsController : Controller
         // Default-account pickers (Revenue / COGS / Inventory) — see SaveDefaultAccounts.
         await PopulateDefaultAccountViewDataAsync(companyId, accounts);
 
+        // GL health: trial-balance net. Debit-normal (Asset/COGS/Expense) minus credit-normal
+        // (Liability/Equity/Revenue) should net to ~0 for balanced books. A non-zero value flags
+        // drift or one-sided postings (often opening balances entered without an offsetting entry).
+        ViewBag.TrialBalanceNet = accounts.Sum(a =>
+            (a.AccountType == AccountType.Asset || a.AccountType == AccountType.CostOfGoods
+                || a.AccountType == AccountType.Expense)
+                ? a.CurrentBalance : -a.CurrentBalance);
+
         return View(grouped);
     }
 

src/PowderCoating.Web/Helpers/HelpKnowledgeBase.cs

@@ -678,6 +678,9 @@ public static class HelpKnowledgeBase
         **Step 5 — Set up your Chart of Accounts (for billing/AP)**
         If you use the Bills and accounting features, go to [Chart of Accounts](/Accounts) and confirm the seeded accounts fit your setup. The wizard seeds a standard set automatically.
 
+        **Trial balance indicator (Chart of Accounts)**
+        The Chart of Accounts page shows a Trial Balance badge: "Balanced" when total debits equal total credits, otherwise how far off the books are (excess debits/credits). A non-zero value usually means opening balances were entered without an offsetting entry, or a one-sided posting. Run Recalculate Balances first; if it persists, review opening balances.
+
         **Default accounts (Chart of Accounts → Set Defaults)**
         On the Chart of Accounts page, the "Default Accounts" card lets you choose a default Revenue, COGS, and Inventory account for your company. These are used automatically when an item or invoice line doesn't specify one: invoice lines fall back to your default Revenue account (then to account 4000 if none is set), and new inventory and catalog items are pre-filled with your default COGS/Inventory accounts. Leave any blank to keep the current behavior. Note: setting BOTH a COGS and an Inventory Asset default makes new items post inventory-consumption COGS (perpetual inventory) — leave them blank if you expense materials when you purchase them.
 

src/PowderCoating.Web/Views/Accounts/Index.cshtml

@@ -36,7 +36,33 @@
     };
 }
 
-<div class="d-flex justify-content-end mb-4">
+@{
+    var tbNet = (decimal)(ViewBag.TrialBalanceNet ?? 0m);
+    var tbBalanced = Math.Abs(tbNet) < 0.01m;
+}
+<div class="d-flex justify-content-between align-items-center mb-4 flex-wrap gap-2">
+    @if (Model.Any())
+    {
+        <div>
+            @if (tbBalanced)
+            {
+                <span class="badge bg-success-subtle text-success-emphasis border border-success-subtle py-2 px-3">
+                    <i class="bi bi-check-circle me-1"></i>Trial balance: Balanced
+                </span>
+            }
+            else
+            {
+                <span class="badge bg-warning-subtle text-warning-emphasis border border-warning-subtle py-2 px-3"
+                      title="Total debits minus total credits. A non-zero value usually means opening balances were entered without an offsetting entry, or a one-sided posting. Run Recalculate Balances; if it persists, review opening balances.">
+                    <i class="bi bi-exclamation-triangle me-1"></i>Trial balance off by @tbNet.ToString("C") (@(tbNet > 0 ? "excess debits" : "excess credits"))
+                </span>
+            }
+        </div>
+    }
+    else
+    {
+        <div></div>
+    }
     <div class="d-flex gap-2">
         <form id="recalcBalancesForm" asp-action="RecalculateBalances" method="post">
             @Html.AntiForgeryToken()

src/PowderCoating.Web/Views/Help/Settings.cshtml

@@ -262,6 +262,15 @@
                 </div>
             </div>
 
+            <h3 class="h6 fw-semibold mt-3 mb-2">Trial Balance Indicator</h3>
+            <p>
+                The top of the Chart of Accounts page shows a <strong>Trial balance</strong> badge. When total
+                debits equal total credits it reads <em>Balanced</em>; otherwise it shows how far off the books
+                are (excess debits or credits). A non-zero value usually means opening balances were entered
+                without an offsetting entry, or a one-sided posting occurred. Run <strong>Recalculate Balances</strong>
+                first; if it persists, review your opening balances or ask your accountant.
+            </p>
+
             <div class="alert alert-permanent alert-warning d-flex gap-2 mb-0" role="alert">
                 <i class="bi bi-exclamation-triangle-fill flex-shrink-0 mt-1"></i>
                 <div>