chore(lint): manual cleanup batch 4 — noNonNullAssertion + small fixes

- noNonNullAssertion (42 → 0): replaced ! assertions with explicit null guards across auth.module, storage.service, pl24-auth, categories.service, catalog.service, parts.service, emex.browser, emex.service, parts-catalogs-auth, pl24-ford-legacy, email.service, database.provider, jobs/processors, psa-variant-selector, vehicles/$id/categories, catalog/$brandName
- buildTree: skip orphaned items instead of asserting map.get
- emex.browser.acquirePage: explicit context check before newPage
- pcat-auth.getIstanbulTime: graceful UTC fallback if Intl parts missing
- email.send: gate on both postalApiUrl + postalApiKey for type narrowing
- categories.service: PSA root-fallback now early-returns when category.vehicleId missing (catalog-only categories don't have a sibling root)
- pl24-ford-legacy: createHash from "node:crypto", URL building uses single template literals, useDefaultParameterLast — required modelYear/engine/gearbox params (callers already supply them)
- pcat-auth: h.origin / h.referer literal-key access
- index.tsx: <button type="button"> on mobile menu toggle
- parts-panel + admin/users: keyboard handler for clickable rows (Enter/Space)
- ford-legacy: useOptionalChain on item.name?.toUpperCase()

Lint count: 155 → 114. Remaining: 121 noExplicitAny + 3 small.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/components/catalog/psa-variant-selector.tsx

@@ -32,7 +32,7 @@ export function PsaVariantSelector({ vehicleId, onSelect }: PsaVariantSelectorPr
     queryKey: ["psa-engines", vehicleId, selectedBody],
     queryFn: () =>
       api.get<VariantItem[]>(
-        `/catalog/vehicles/${vehicleId}/psa-engines?body=${encodeURIComponent(selectedBody!)}`,
+        `/catalog/vehicles/${vehicleId}/psa-engines?body=${encodeURIComponent(selectedBody ?? "")}`,
       ),
     enabled: !!vehicleId && !!selectedBody,
   });
@@ -41,7 +41,7 @@ export function PsaVariantSelector({ vehicleId, onSelect }: PsaVariantSelectorPr
     queryKey: ["psa-gearboxes", vehicleId, selectedBody, selectedEngine],
     queryFn: () =>
       api.get<VariantItem[]>(
-        `/catalog/vehicles/${vehicleId}/psa-gearboxes?body=${encodeURIComponent(selectedBody!)}&engine=${encodeURIComponent(selectedEngine!)}`,
+        `/catalog/vehicles/${vehicleId}/psa-gearboxes?body=${encodeURIComponent(selectedBody ?? "")}&engine=${encodeURIComponent(selectedEngine ?? "")}`,
       ),
     enabled: !!vehicleId && !!selectedBody && !!selectedEngine,
   });
@@ -58,7 +58,8 @@ export function PsaVariantSelector({ vehicleId, onSelect }: PsaVariantSelectorPr
 
   const handleEngineSelect = (code: string | "_all_") => {
     if (code === "_all_") {
-      onSelect(selectedBody!, "_all_", "_all_");
+      if (!selectedBody) return;
+      onSelect(selectedBody, "_all_", "_all_");
       return;
     }
     setSelectedEngine(code);
@@ -67,7 +68,8 @@ export function PsaVariantSelector({ vehicleId, onSelect }: PsaVariantSelectorPr
 
   const handleGearboxSelect = (code: string | "_all_") => {
     if (code === "_all_") {
-      onSelect(selectedBody!, selectedEngine!, "_all_");
+      if (!selectedBody || !selectedEngine) return;
+      onSelect(selectedBody, selectedEngine, "_all_");
       return;
     }
     setSelectedGearbox(code);

apps/web/src/components/schema/parts-panel.tsx

@@ -120,6 +120,12 @@ export function PartsPanel({ parts, vehicleId, categoryId }: PartsPanelProps) {
                   onMouseEnter={() => setHighlightedGroup(group)}
                   onMouseLeave={() => setHighlightedGroup(null)}
                   onClick={() => setSelectedGroup(selectedGroup === group ? null : group)}
+                  onKeyDown={(e) => {
+                    if (e.key === "Enter" || e.key === " ") {
+                      e.preventDefault();
+                      setSelectedGroup(selectedGroup === group ? null : group);
+                    }
+                  }}
                 >
                   <td className="px-3 py-2 text-muted-foreground">{part.hotspotIndex}</td>
                   <td className="px-3 py-2">

apps/web/src/routes/dashboard/admin/users.tsx

@@ -461,7 +461,15 @@ function AdminUsersPage() {
                 <div
                   key={u.id}
                   className="grid cursor-pointer items-center gap-4 px-6 py-4 transition-colors hover:bg-muted/50 lg:grid-cols-7"
+                  role="button"
+                  tabIndex={0}
                   onClick={() => setSelectedUserId(u.id)}
+                  onKeyDown={(e) => {
+                    if (e.key === "Enter" || e.key === " ") {
+                      e.preventDefault();
+                      setSelectedUserId(u.id);
+                    }
+                  }}
                 >
                   <div>
                     <p className="font-medium">{u.name}</p>

apps/web/src/routes/dashboard/catalog_/$brandName/index.tsx

@@ -134,9 +134,9 @@ function CatalogModelsPage() {
             <Skeleton key={__k} className="h-24 w-full rounded-xl" />
           ))}
         </div>
-      ) : isMultiCatalog && !activeCatalog ? (
+      ) : isMultiCatalog && !activeCatalog && catalogs ? (
         // Sub-catalog selector
-        <CatalogSelector catalogs={catalogs!} brandName={brandName} brandLabel={decodedBrandName} />
+        <CatalogSelector catalogs={catalogs} brandName={brandName} brandLabel={decodedBrandName} />
       ) : modelsLoading ? (
         <div>
           <div className="mb-4 flex items-center gap-2 text-sm text-muted-foreground">

apps/web/src/routes/dashboard/vehicles_/$id/categories_/$categoryId.tsx

@@ -143,12 +143,13 @@ function VehicleCategoryPage() {
 
       {/* Parent category — show children */}
       {hasChildren &&
+        data?.children &&
         (viewMode === "grid" ? (
-          <CategoryGrid categories={data.children!} vehicleId={id} />
+          <CategoryGrid categories={data.children} vehicleId={id} />
         ) : viewMode === "tree" ? (
-          <CategoryTree categories={data.children!} vehicleId={id} />
+          <CategoryTree categories={data.children} vehicleId={id} />
         ) : (
-          <CategoryColumns categories={data.children!} vehicleId={id} />
+          <CategoryColumns categories={data.children} vehicleId={id} />
         ))}
 
       {/* Leaf category — show schema viewer */}

apps/web/src/routes/index.tsx

@@ -620,7 +620,7 @@ function HomePage() {
             >
               {isDark ? <Sun className="size-4" /> : <Moon className="size-4" />}
             </button>
-            <button onClick={() => setMobileMenuOpen(!mobileMenuOpen)}>
+            <button type="button" onClick={() => setMobileMenuOpen(!mobileMenuOpen)}>
               {mobileMenuOpen ? <X className="size-6" /> : <Menu className="size-6" />}
             </button>
           </div>