Add AI Quick Quote widget and inline customer reassignment

- New AI Quick Quote floating button: staff type a verbal description to
  get an instant price estimate for phone/walk-in customers; detected
  color names are fuzzy-matched against inventory for stock status;
  saves draft quote under a Walk-In / Phone customer with one click
- Inline customer change on Quote Details and Job Details: always-visible
  native select with inline confirmation banner (no TomSelect dependency);
  ChangeCustomer AJAX endpoints on QuotesController and JobsController
- Quote Edit page: customer dropdown is now editable (lock removed)
- Fix AutoMapper missing CatalogCategory -> UpdateCategoryDto mapping
  that caused a crash on the catalog category Edit page
- Help docs and AI knowledge base updated for all three features

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

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

@@ -545,6 +545,37 @@
             </div>
         </section>
 
+        <section id="changing-customer" class="mb-5">
+            <h2 class="h4 fw-bold border-bottom pb-2 mb-3">
+                <i class="bi bi-person-gear text-primary me-2"></i>Changing the Customer
+            </h2>
+            <p>
+                The customer on a job can be changed at any time from the Job Details page — no need to
+                delete and re-create the job. This is useful when:
+            </p>
+            <ul class="mb-3">
+                <li class="mb-1">A job was created under the <em>Walk-In / Phone</em> placeholder and the real customer is added later.</li>
+                <li class="mb-1">A job was accidentally assigned to the wrong customer.</li>
+                <li class="mb-1">A job converted from a quote needs to be moved to a different customer record.</li>
+            </ul>
+
+            <h3 class="h6 fw-semibold mt-3 mb-2">How to change the customer</h3>
+            <ol class="mb-3">
+                <li class="mb-2">Open the job from <strong>Operations &rsaquo; Jobs</strong> and go to its Details page.</li>
+                <li class="mb-2">Find the <strong>Customer</strong> field in the job header — it appears as a dropdown showing the current customer.</li>
+                <li class="mb-2">Select a different customer from the dropdown.</li>
+                <li class="mb-2">A confirmation banner appears: <em>"Change customer to [Name]?"</em> — click <strong>Save</strong> to confirm or <strong>Cancel</strong> to revert.</li>
+            </ol>
+            <div class="alert alert-permanent alert-info d-flex gap-2 mb-0" role="alert">
+                <i class="bi bi-info-circle flex-shrink-0 mt-1"></i>
+                <div>
+                    The customer can also be changed on the <strong>Edit Job</strong> page using the Customer
+                    dropdown there. Any invoices or deposits already linked to the job are not automatically
+                    moved — update those separately if needed.
+                </div>
+            </div>
+        </section>
+
         <section id="blank-work-order" class="mb-5">
             <h2 class="h5 fw-semibold mb-3">Blank Work Order</h2>
             <p>
@@ -611,6 +642,7 @@
                     <a class="nav-link py-1 px-3 small text-body" href="#shop-display-and-board">Shop Display &amp; Priority Board</a>
                     <a class="nav-link py-1 px-3 small text-body" href="#part-intake">Part Intake</a>
                     <a class="nav-link py-1 px-3 small text-body" href="#shop-mobile">Shop Mobile</a>
+                    <a class="nav-link py-1 px-3 small text-body" href="#changing-customer">Changing the Customer</a>
                     <a class="nav-link py-1 px-3 small text-body" href="#blank-work-order">Blank Work Order</a>
                 </nav>
             </div>