feat(eoi): template-aware generate-EOI dialog

The EOI dialog now lists "Documenso Standard EOI" (default) plus any
seeded in-app EOI templates and routes the submit to the dual-path
generate-and-sign endpoint with the correct pathway:

  - "documenso-template" sentinel id → pathway: documenso-template
  - any other template id → pathway: inapp

Signers are derived server-side from EoiContext for both pathways when
the template type is EOI (interest's client + hardcoded developer +
approver), so the dialog doesn't collect them. Non-EOI templates still
require explicit signers.

Drops the legacy `client.yachtLengthFt` prerequisite check (yacht is now
a first-class entity) and replaces it with hasYacht based on
interest.yachtId. Tests updated; 646/646 green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/integration/document-templates-generate-and-sign.test.ts

@@ -206,16 +206,53 @@ describe('generateAndSign — inapp pathway', () => {
     expect(docRow?.fileId).toBeTruthy();
   });
 
-  it('throws ValidationError when signers array is empty', async () => {
+  it('auto-derives signers for EOI templates when none are provided', async () => {
+    const client = await import('@/lib/services/documenso-client');
+    vi.mocked(client.createDocument).mockResolvedValue({
+      id: 'doc-auto-signers',
+      status: 'PENDING',
+      recipients: [],
+    });
+    vi.mocked(client.sendDocument).mockResolvedValue({
+      id: 'doc-auto-signers',
+      status: 'PENDING',
+      recipients: [],
+    });
+
+    await generateAndSign(
+      setup.inAppTemplateId,
+      setup.portId,
+      { clientId: setup.clientId, interestId: setup.interestId },
+      [],
+      'inapp',
+      { ...meta, portId: setup.portId },
+    );
+
+    expect(client.createDocument).toHaveBeenCalledOnce();
+    const recipients = vi.mocked(client.createDocument).mock.calls[0]![2];
+    expect(recipients).toHaveLength(3);
+    expect(recipients[0]?.name).toBe('Dual Path Client');
+    expect(recipients[1]?.name).toBe('David Mizrahi');
+    expect(recipients[2]?.role).toBe('approver');
+  });
+
+  it('throws ValidationError when non-EOI template has no signers', async () => {
+    const [other] = await db
+      .insert(documentTemplates)
+      .values({
+        portId: setup.portId,
+        name: 'Plain Letter',
+        templateType: 'welcome_letter',
+        bodyHtml: '<p>x</p>',
+        createdBy: 'test',
+      })
+      .returning();
+
     await expect(
-      generateAndSign(
-        setup.inAppTemplateId,
-        setup.portId,
-        { clientId: setup.clientId, interestId: setup.interestId },
-        [],
-        'inapp',
-        { ...meta, portId: setup.portId },
-      ),
+      generateAndSign(other!.id, setup.portId, { clientId: setup.clientId }, [], 'inapp', {
+        ...meta,
+        portId: setup.portId,
+      }),
     ).rejects.toThrow(ValidationError);
   });