feat(workflows): wire booking document actions (prepare_invoice/contract + send_document)

Implements the draft-seam booking cutover so the booking_invoice_only flow
becomes enableable. The booking flows trigger on quote.accepted, so the run
entity is the quote:

- prepare_invoice: convertToInvoiceOnly({draft:true}) creates the invoice(s)
  on HOLD (scheduled_send_at NULL, status stays 'scheduled') so the scheduler
  never auto-sends before the review gate; crash-recovery recovers drafts by
  the quote's deal_uuid. Stores ids in ctx.vars.preparedInvoiceIds.
- prepare_contract: createFromQuote (idempotent via converted_contract_id).
- send_document: dispatches the prepared draft (invoice -> sendInvoice each id,
  contract -> sendContract).
- resolveActor: quote creator -> workflow creator -> first admin.
- prepare_contract/prepare_invoice/send_document removed from the enable-guard
  list; prepare_event/prepare_quote/prepare_gallery/reserve_date still guarded,
  so booking_full/booking_simple stay blocked until the event-path increment.

Fixes a latent single-connection SQLite deadlock these unattended paths would
hit: getAppSetting/logActivity/adminActor read or write the global db, which
deadlocks when issued inside an open knex transaction. Thread the active trx
through getAppSetting, logActivity, nextInvoiceNumber, nextContractNumber, the
spawnInstallmentInvoices audit log, and hoist adminActor before createFromQuote's
transaction. convertToInvoiceOnly now logs after commit and returns invoiceIds.

Adds bookingCutover integration test (hold-mode null send-at, normal scheduled
contrast, contract path no-deadlock) and a route test that the now-implemented
booking invoice actions can be enabled.

backend/src/services/contractService.js

@@ -167,7 +167,10 @@ function formatNumberInTemplate(format, year, seq) {
  * emit `C-2026-AB12C3` after 5 retries.
  */
 async function nextContractNumber(trx) {
-  const format = (await getAppSetting('crm_contracts_number_format')) || 'C-{YEAR}-{SEQ:04d}';
+  // Read through `trx` when present — getAppSetting on the global db inside an
+  // open transaction deadlocks the single-connection SQLite pool (the booking
+  // flow's prepare_contract action runs createFromQuote unattended).
+  const format = (await getAppSetting('crm_contracts_number_format', null, trx || db)) || 'C-{YEAR}-{SEQ:04d}';
   const year = new Date().getFullYear();
   const seq = await claimNextSequence('contract', year, trx);
   return formatNumberInTemplate(format, year, seq);
@@ -1661,6 +1664,11 @@ async function createFromQuote(quoteId, adminId) {
   const hasQuoteContractBackPointer = await hasColumnCached('quotes', 'converted_contract_id');
   const hasContractEventCols = await hasColumnCached('contracts', 'event_name');
 
+  // Resolve the actor BEFORE opening the transaction — adminActor reads
+  // admin_users via the global db, which deadlocks the single-connection
+  // SQLite pool if evaluated inside the trx (prepare_contract runs unattended).
+  const actor = await adminActor(adminId);
+
   return await db.transaction(async (trx) => {
     // Pass trx so the sequence claim joins our outer transaction —
     // SQLite deadlocks otherwise (1-connection default).
@@ -1735,9 +1743,11 @@ async function createFromQuote(quoteId, adminId) {
     }
 
     try {
+      // Pass `trx` so the audit insert rides the transaction's connection;
+      // the global db here deadlocks the single-connection SQLite pool.
       await logActivity('contract_created_from_quote',
         { contractId, contractNumber, quoteId: quote.id, quoteNumber: quote.quote_number },
-        null, await adminActor(adminId));
+        null, actor, trx);
     } catch (_) { /* logging is best-effort */ }
     logger.info('Contract created from quote', { adminId, contractId, contractNumber, quoteId: quote.id });
     return { contractId, alreadyConverted: false };