Document AI Catalog Price Check in knowledge base and help article

- HelpKnowledgeBase: full AI price check section (verdicts, confidence,
  category paths, run limit, how to use, common questions)
- Inventory help article: new 'AI Catalog Price Check' section with
  verdicts, step-by-step instructions, caveats, and on-page nav link

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

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

@@ -430,6 +430,51 @@
             </div>
         </section>
 
+        <section id="ai-price-check" class="mb-5">
+            <h2 class="h4 fw-bold border-bottom pb-2 mb-3">
+                <i class="bi bi-robot text-primary me-2"></i>AI Catalog Price Check
+            </h2>
+            <p>
+                The AI Price Check reviews every active, priced item in your
+                <a asp-controller="CatalogItems" asp-action="Index">Catalog Items</a> list against your
+                shop's actual operating costs. It estimates a realistic surface area and processing time
+                for each item, calculates a cost floor, and compares that to your current price — flagging
+                anything that may be losing money, leaving margin on the table, or priced above market rates.
+            </p>
+
+            <h3 class="h6 fw-semibold mt-3 mb-2">Verdicts</h3>
+            <ul class="mb-3">
+                <li class="mb-2"><strong>Below Cost</strong> — price is at or below the estimated cost floor. The shop loses money on every sale of this item.</li>
+                <li class="mb-2"><strong>Thin Margin</strong> — price covers costs but falls below your target margin percentage.</li>
+                <li class="mb-2"><strong>High</strong> — price appears significantly above typical market rates, which may cost you work.</li>
+                <li class="mb-2"><strong>OK</strong> — price is within a reasonable range given your costs and market context.</li>
+            </ul>
+
+            <h3 class="h6 fw-semibold mt-3 mb-2">How to run it</h3>
+            <ol class="mb-3">
+                <li class="mb-2">Make sure your <a asp-controller="CompanySettings" asp-action="Index">operating costs</a> are up to date — stale rates produce inaccurate verdicts.</li>
+                <li class="mb-2">Go to <a asp-controller="CatalogItems" asp-action="Index">Catalog Items</a> and click <strong>AI Price Check</strong> in the top-right.</li>
+                <li class="mb-2">Click <strong>Analyze Catalog with AI</strong>. A progress overlay appears while the analysis runs (allow 7–10 minutes for large catalogs).</li>
+                <li class="mb-2">Review results sorted by severity — Below Cost items appear first. Click <strong>Edit Price</strong> on any item to update it directly from the results page.</li>
+            </ol>
+
+            <h3 class="h6 fw-semibold mt-3 mb-2">Things to know</h3>
+            <ul class="mb-3">
+                <li class="mb-2"><strong>Run limit:</strong> Analysis can be run once per quarter (90 days). The button shows the next available date when a recent run exists.</li>
+                <li class="mb-2"><strong>Confidence levels:</strong> Each result shows High, Medium, or Low confidence. Vague item names like "Custom Part" will be Low — verify those manually.</li>
+                <li class="mb-2"><strong>Category paths matter:</strong> The AI uses the full category path (e.g. "Cerakote &rsaquo; Firearms") to determine the coating type. Make sure specialty items are in the correct category.</li>
+                <li class="mb-2"><strong>$0 items skipped:</strong> Placeholder items and category headers with no price are automatically excluded from analysis.</li>
+            </ul>
+
+            <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>
+                    Results are estimates based on industry knowledge and your shop's rates. Always apply
+                    your own judgment before changing prices — especially for items flagged as Low confidence.
+                </div>
+            </div>
+        </section>
+
     </div>
 
     <div class="col-lg-3 d-none d-lg-block">
@@ -449,6 +494,7 @@
                     <a class="nav-link py-1 px-3 small text-body" href="#powder-insights">Powder Insights</a>
                     <a class="nav-link py-1 px-3 small text-body" href="#inventory-categories">Inventory Categories &amp; Is Coating</a>
                     <a class="nav-link py-1 px-3 small text-body" href="#powder-usage">Powder Usage on Jobs</a>
+                    <a class="nav-link py-1 px-3 small text-body" href="#ai-price-check">AI Catalog Price Check</a>
                 </nav>
             </div>
         </div>