feat(10-redo-C): CRM leads module — schema, services, UI (Phase 10 redo)

Stage C of staged Phase 10 redo. Restores dangling phase10-wip work:
- schema.ts: leads expansion + activities/reminders tables + relations
- lead-service.ts / lead-validators.ts service layer
- /admin/leads list + detail + actions, LeadTable/LeadDetail/LeadForm
- LogActivityModal, SendQuoteModal, FollowUpWidget on dashboard
- migration 0005 (applied to prod DB in Stage B, along with
  previously-missing 0001/0003/0004 — root cause of all post-deploy
  500s: prod DB had no migrations applied since 0000)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/app/admin/leads/page.tsx

@@ -0,0 +1,25 @@
+import { Suspense } from "react";
+import { getAllLeads } from "@/lib/lead-service";
+import { LeadTable } from "@/components/admin/leads/LeadTable";
+import { CreateLeadModal } from "@/components/admin/leads/LeadForm";
+
+async function LeadsList() {
+  const leads = await getAllLeads();
+
+  return (
+    <div className="space-y-6">
+      <div className="flex justify-between items-center">
+        <h1 className="text-3xl font-bold">Lead Pipeline</h1>
+        <CreateLeadModal />
+      </div>
+
+      <Suspense fallback={<div className="animate-pulse">Loading...</div>}>
+        <LeadTable leads={leads} />
+      </Suspense>
+    </div>
+  );
+}
+
+export default function LeadsPage() {
+  return <LeadsList />;
+}