Cover business interests via a proper continuity instrument

Same gap as land parcels: business assets were routed into the generic
trust fields (trustee/successor/beneficiaries), which don't fit — a
business needs a continuity instrument, not a trustee holding title.

New "business-continuity" channel in Nomination Registry, modelled on the
digital-waqif docs repo's own business-succession framework (Clause 9):
- Structure selector (sole proprietorship / partnership / company). Sole
  proprietorship surfaces an explicit warning: it legally dies with the
  owner, so the only fast-path options are converting to a company or
  dedicating as a waqf-owned enterprise.
- Instrument selector: partnership continuation clause, shareholder
  buy-sell agreement (the standard fast-path for company shares, often
  Takaful-funded), or a direct redirect to Family Waqf Designator for a
  waqf-owned enterprise (nothing duplicated here — reuses that module).
- Dedicated business-continuity-draft.txt export, same treatment as the
  trust deed and waqfiyya exports.
- Death Trigger packet text updated with the business-specific execution
  action (execute buy-sell / continuation clause, file Takaful claim if
  funded — a private agreement between owners, not a probate filing).

e2e-business.cjs: new suite covering exposed->warning->instrument
selection->export->100% coverage->execution packet, plus the
waqf-enterprise redirect disabling the Add button. 10/10 passing.
Re-verified e2e-uat.cjs (32/32), e2e-fastpath.cjs (16/16), and
e2e-trust.cjs (12/12) — 70/70 total, no regressions.

src/lib/DeathTrigger.svelte

@@ -77,6 +77,8 @@
         ? 'ACTION: File a death claim with the Takaful/insurance provider. As a nominated\ntrust under Insurance Act 1996 s.166 (or Takaful equivalent), payout goes directly\nto the named beneficiary — no probate required.'
         : row.channel === 'bank-mandate'
         ? 'ACTION: Notify the bank with the death certificate and the death-mandate /\njoint-account documentation on file. Funds release per the mandate terms — this\nis a bank process, not a court process.'
+        : row.channel === 'business-continuity'
+        ? 'ACTION: Execute the pre-agreed buy-sell provision or partnership continuation\nclause on file. If Takaful-funded, file the Takaful death claim to release the\nbuyout funds. This is a private agreement between co-owners/shareholders, not a\nprobate filing.'
         : 'ACTION: Contact the trustee/nominee holder to execute the pre-arranged transfer\nunder the trust deed. This is an internal trustee record update, not a probate\nfiling.',
       '',
       'This packet was generated by Nur Falah on a local device. It is a drafting aid;',