feat(landing): multi-company FAQ, Auto-Map wording, remove dormant sections

- §4: new FAQ 'I keep books for several companies — can I manage them all
  here?' surfacing multi-graph-per-org (verified: Organization.graphs
  one-to-many). Framed on the isolated-books-per-company capability only;
  makes no team/collaboration claim either way.
- §2.9: 'you review and approve' -> 'review and adjust' (MappingOperator
  auto-writes mappings above its confidence threshold; not a hard gate).
- §2.10: delete the 6 superseded, unimported landing sections
  (FeaturesSection, WorkflowSection, ReportCreator, OutputFormats,
  AIReportingSection, OpenSourceSection) — they carried the removed
  overclaims (Plaid-live, 'autonomous', 'Coming Soon'). Content is re-told
  honestly in the new sections; 0 references confirmed.

Author: jfrench9

src/components/landing/AIReportingSection.tsx

@@ -28,8 +28,8 @@ const faqs: { q: string; a: ReactNode }[] = [
       <>
         No. AI Auto-Map proposes the US-GAAP mapping for your chart of accounts
         with confidence scores, and the rule engine validates every entry before
-        you lock a period. You review and approve — the taxonomy work happens
-        for you.
+        you lock a period. You review and adjust — the taxonomy work happens for
+        you.
       </>
     ),
   },
@@ -44,6 +44,17 @@ const faqs: { q: string; a: ReactNode }[] = [
       </>
     ),
   },
+  {
+    q: 'I keep books for several companies — can I manage them all here?',
+    a: (
+      <>
+        Yes. Each company&apos;s books live in their own isolated graph —
+        connect QuickBooks per company, close each period independently, and
+        switch between them from one account. It&apos;s built for accountants
+        and bookkeepers who run more than one set of books.
+      </>
+    ),
+  },
   {
     q: 'How do I get started, and what does it cost?',
     a: (