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/lib/services/interest-berths.service.ts

@@ -143,6 +143,10 @@ export interface InterestBerthWithDetails extends InterestBerth {
   mooringNumber: string | null;
   area: string | null;
   status: string | null;
+  /** Soft-pin marker: when 'manual', the berth's pinned status wins over
+   *  this link's is_specific_interest signal on the public map, so the UI
+   *  warns the rep that "Specifically pitching" won't surface Under Offer. */
+  statusOverrideMode: string | null;
   lengthFt: string | null;
   widthFt: string | null;
   draftFt: string | null;
@@ -169,6 +173,7 @@ export async function listBerthsForInterest(
       mooringNumber: berths.mooringNumber,
       area: berths.area,
       status: berths.status,
+      statusOverrideMode: berths.statusOverrideMode,
       lengthFt: berths.lengthFt,
       widthFt: berths.widthFt,
       draftFt: berths.draftFt,

src/lib/services/maintenance-module.service.ts

@@ -0,0 +1,59 @@
+/**
+ * Maintenance module gate. Port-scoped on/off switch for the per-berth
+ * maintenance surface (the berth "Maintenance" tab, its log API, and the
+ * maintenance-reminder notification preference).
+ *
+ * Defaults to ENABLED so existing ports keep the feature on deploy.
+ * When an admin turns it off:
+ *  - the Maintenance tab disappears from the berth detail page (gated via
+ *    the port-resolved maintenanceModuleByPort prop on the layout →
+ *    port-provider → `useMaintenanceModuleEnabled()`)
+ *  - the maintenance log routes reject reads/writes at the boundary
+ *    (`assertMaintenanceModuleEnabled` → 404)
+ *  - previously-recorded maintenance logs are preserved (no destructive
+ *    cleanup) so re-enabling restores everything
+ */
+
+import { and, eq, isNull, or } from 'drizzle-orm';
+
+import { db } from '@/lib/db';
+import { systemSettings } from '@/lib/db/schema/system';
+import { NotFoundError } from '@/lib/errors';
+
+/**
+ * Resolve whether the Maintenance module is currently active for the given
+ * port. Reads from `system_settings.maintenance_module_enabled` (port-
+ * scoped row first, then global row, then registry default = true).
+ *
+ * Defaulting to enabled mirrors how the feature behaved before the toggle
+ * existed: deploying this change to a port that has never configured the
+ * setting leaves the feature visible.
+ */
+export async function isMaintenanceModuleEnabled(portId: string): Promise<boolean> {
+  const settingRow = await db
+    .select({ value: systemSettings.value })
+    .from(systemSettings)
+    .where(
+      and(
+        eq(systemSettings.key, 'maintenance_module_enabled'),
+        or(eq(systemSettings.portId, portId), isNull(systemSettings.portId)),
+      ),
+    )
+    .limit(1);
+  // Stored JSONB shape is the raw boolean; only an explicit `false` turns
+  // the module off — missing row / true / unrecognized shape => enabled.
+  if (settingRow[0]?.value === false) return false;
+  return true;
+}
+
+/**
+ * Throw `NotFoundError` (→ 404) when the Maintenance module is disabled.
+ * Defense-in-depth for the maintenance log routes; the UI independently
+ * hides the tab so a rep never sees a link that would 404.
+ */
+export async function assertMaintenanceModuleEnabled(portId: string): Promise<void> {
+  const enabled = await isMaintenanceModuleEnabled(portId);
+  if (!enabled) {
+    throw new NotFoundError('Maintenance module is not enabled for this port.');
+  }
+}