feat(berths): inline spec-PDF preview, manual-pin badge, maintenance module toggle, under-offer popover

Post-cutover UAT batch #3:
- #62 Spec tab renders the current berth spec PDF inline (lazy PdfViewer,
  toggleable, default-open) + explicit download. Interest Documents tab
  already previews/downloads linked deal docs inline (verified).
- #57 Surface berths.status_override_mode through the interest-berths API;
  linked-berth rows show an amber "Pin overrides pitch" badge + corrected
  consequence copy when a berth is specifically-pitched but manually pinned
  (the soft-pin wins on the public map).
- #63 New maintenance-module gate (maintenance_module_enabled, default on):
  registry + admin Settings toggle, maintenance-module.service, port-provider
  useMaintenanceModuleEnabled, layout wiring, buildBerthTabs hides the
  Maintenance tab when off, and both maintenance log routes assert the gate.
- #66 BerthOccupancyChip: >1 competing interest opens a popover listing every
  deal (name + stage + in-EOI/primary + link); single stays a direct link.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/providers/port-provider.tsx

@@ -16,6 +16,10 @@ interface PortContextValue {
    *  Resolved server-side in the dashboard layout. Consumers read via
    *  `useTenanciesModuleEnabled()`. */
   tenanciesModuleByPort: Record<string, boolean>;
+  /** Per-port Maintenance-module flag. Resolved server-side in the
+   *  dashboard layout; consumers read via `useMaintenanceModuleEnabled()`.
+   *  Defaults to enabled (unset port => true). */
+  maintenanceModuleByPort: Record<string, boolean>;
 }
 
 const PortContext = createContext<PortContextValue>({
@@ -24,6 +28,7 @@ const PortContext = createContext<PortContextValue>({
   currentPortId: null,
   currentPortSlug: null,
   tenanciesModuleByPort: {},
+  maintenanceModuleByPort: {},
 });
 
 interface PortProviderProps {
@@ -31,6 +36,7 @@ interface PortProviderProps {
   ports: Port[];
   defaultPortId: string | null;
   tenanciesModuleByPort?: Record<string, boolean>;
+  maintenanceModuleByPort?: Record<string, boolean>;
 }
 
 export function PortProvider({
@@ -38,6 +44,7 @@ export function PortProvider({
   ports,
   defaultPortId,
   tenanciesModuleByPort = {},
+  maintenanceModuleByPort = {},
 }: PortProviderProps) {
   const params = useParams();
   const portSlugFromUrl = params?.portSlug as string | undefined;
@@ -87,6 +94,7 @@ export function PortProvider({
         currentPortId: currentPort?.id ?? null,
         currentPortSlug: currentPort?.slug ?? null,
         tenanciesModuleByPort,
+        maintenanceModuleByPort,
       }}
     >
       {children}
@@ -106,3 +114,13 @@ export function useTenanciesModuleEnabled(): boolean {
   if (!currentPortId) return false;
   return tenanciesModuleByPort[currentPortId] ?? false;
 }
+
+/** Read the maintenance-module-enabled flag for the currently-active port.
+ *  Defaults to ENABLED (true) when unset so the feature stays visible
+ *  unless an admin has explicitly turned it off. Server-side resolved in
+ *  the dashboard layout — synchronous read, no fetch latency/flicker. */
+export function useMaintenanceModuleEnabled(): boolean {
+  const { currentPortId, maintenanceModuleByPort } = useContext(PortContext);
+  if (!currentPortId) return true;
+  return maintenanceModuleByPort[currentPortId] ?? true;
+}