fix(quotes): persist letterhead choice on terminal-status quotes too

The first letterhead-persistence fix (1e3121d) gated the WHOLE PB
write for generateQuotePdf's operator-choice persistence behind
"quote.status is not terminal" -- because terminal statuses
(approved/emailed/complete/cancelled/sending) deliberately skip the
pdf_generated_at re-stamp.

But regenerating a PDF on an already-terminal quote (e.g. clicking
"ISherwood" on an already-`emailed` quote from the process page) is
a normal, supported operator action -- confirmed live: it renders
the right letterhead and toasts "quote kept at emailed". That regen
hit the terminal branch and skipped the PB write entirely, so
company_letterhead never updated. A later auto-regen (sendQuoteEmail's
staleness check, e.g. triggered by a markup edit) then fell back to
the stale stored value and shipped the wrong letterhead again --
reproducing the original bug through a path the first fix didn't
cover.

Verified against the live quote via a direct PocketBase read
(bypassing app/MCP caching): company_letterhead was unchanged by the
first fix's terminal-status regen, and is now correctly persisted
while pdf_generated_at/status stay untouched as intended.

Split the letterhead write out from the timestamp/status write so it
always persists on an explicit operator choice regardless of quote
status. Added a regression test for the terminal-status + explicit
letterhead case.

Also syncs the n8n "Quote Outbound Send" workflow snapshot with two
more live fixes made during testing:
- Build attachments list: this.helpers.getBinaryDataBuffer() takes
  an item INDEX (number), not an item object -- per n8n's own docs.
  Was passing the item object, which threw an opaque non-Error value
  on every real send.
- Send Email (SMTP): the html field injected the plain-text
  email_message (with literal \n breaks) straight into HTML, so
  clients collapsed every paragraph into one block. Now converts \n
  to <br> first.
Also captures that the four WhatsApp-notify nodes and the workflow
itself are currently disabled/inactive in the live instance (manual
n8n edits during testing, not part of this fix).

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

src/lib/server/quote-pdf-service.test.ts

@@ -802,6 +802,68 @@ describe("generateQuotePdf", () => {
       .getOne<{ company_letterhead: string }>(quote.id);
     expect(after.company_letterhead).toBe("ISHERWOOD");
   });
+
+  it("persists the operator's letterhead choice even when the quote is already terminal (e.g. emailed)", async () => {
+    // Regression: the first fix for the silent letterhead-flip bug
+    // gated the WHOLE persistence write (letterhead included)
+    // behind "quote.status is not terminal" — because terminal
+    // statuses (approved/emailed/complete/cancelled/sending)
+    // deliberately skip the pdf_generated_at re-stamp. But the
+    // process page's CNL/ISherwood buttons are usable on an
+    // already-`emailed` quote (regenerating a PDF after the first
+    // send is a normal operator action, confirmed live: clicking
+    // ISherwood on an `emailed` quote renders an ISHERWOOD PDF and
+    // toasts "quote kept at emailed"). That regen hit the terminal
+    // branch, rendered correctly, but skipped the PB write
+    // entirely — so `company_letterhead` never updated, and a
+    // later auto-regen (sendQuoteEmail's staleness check, e.g.
+    // triggered by a markup edit) fell back to the stale CNL value
+    // and shipped the wrong letterhead again. Confirmed against the
+    // real quote via a direct PocketBase read: company_letterhead
+    // and pdf_generated_at were both untouched by the "first fix".
+    const { quote } = await seedQuoteWithPdf();
+    await pbMock.collection("quotes").update(quote.id, {
+      status: "emailed",
+    });
+    await pbMock.collection("quote_items").create({
+      quote: quote.id,
+      description: "M16 hex bolt",
+      quantity: 1,
+      cost_price: 2.39,
+      selling_price: 3.11,
+      markup: 30,
+      supplier: "sup-acme",
+      is_processed: true,
+      moved_to_quote: null,
+    });
+
+    const before = await pbMock
+      .collection("quotes")
+      .getOne<{ pdf_generated_at: string }>(quote.id);
+
+    const outcome = await generateQuotePdf(quote.id, {
+      letterhead: "ISHERWOOD",
+    });
+    expect(outcome.kind).toBe("ok");
+    if (outcome.kind !== "ok") throw new Error("expected ok outcome");
+    expect(outcome.companyLetterhead).toBe("ISHERWOOD");
+    // Status stays exactly as it was — terminal statuses are never
+    // silently flipped by a PDF regen.
+    expect(outcome.status).toBe("emailed");
+
+    const after = await pbMock
+      .collection("quotes")
+      .getOne<{ company_letterhead: string; pdf_generated_at: string; status: string }>(
+        quote.id,
+      );
+    // The letterhead choice IS persisted now, even on a terminal
+    // quote — this is the fix.
+    expect(after.company_letterhead).toBe("ISHERWOOD");
+    // But pdf_generated_at and status are untouched, exactly as
+    // before — terminal-status semantics are preserved.
+    expect(after.pdf_generated_at).toBe(before.pdf_generated_at);
+    expect(after.status).toBe("emailed");
+  });
 });
 
 // ─────────────────────────────────────────────────────────────────────────────

src/lib/server/quote-pdf-service.ts

@@ -475,6 +475,21 @@ export async function generateQuotePdf(
           ...(autoClaimUserId ? { claimed_by: autoClaimUserId } : {}),
           ...letterheadPersistence,
         });
+      } else if (Object.keys(letterheadPersistence).length > 0) {
+        // Terminal statuses (approved/emailed/complete/cancelled/
+        // sending) skip the pdf_generated_at re-stamp above on
+        // purpose, but an explicit operator letterhead choice must
+        // still be persisted regardless of status. This is the gap
+        // that let the silent letterhead-flip bug survive the first
+        // fix: regenerating on an already-`emailed` quote (exactly
+        // what the process page's CNL/ISherwood buttons allow) hit
+        // this terminal branch, rendered the right letterhead, but
+        // never wrote it back — so a later auto-regen (e.g. from
+        // sendQuoteEmail's staleness check after a markup edit)
+        // fell back to the stale stored value and shipped the wrong
+        // letterhead again. Deliberately does NOT touch
+        // pdf_generated_at or status here.
+        await pb.collection("quotes").update(quoteId, letterheadPersistence);
       }
     } else {
       pdfGeneratedAt = new Date().toISOString();