feat(eoi): in-app pathway fills the same source PDF as Documenso

When the in-app pathway is used for EOI templates, we now load the same
source PDF that the Documenso template uploads and fill its AcroForm
fields with values from EoiContext via pdf-lib. Field names mirror the
Documenso template's formValues keys exactly (Name, Email, Address,
Yacht Name, Length, Width, Draft, Berth Number + Lease_10 / Purchase
checkboxes), so both pathways produce equivalent legal documents — only
the renderer differs.

The form is left interactive (not flattened) so a recipient can still
adjust values before signing. Non-EOI templates (welcome letters,
acknowledgments, etc.) keep using the existing HTML→pdfme path.

Adds:
- pdf-lib direct dep
- src/lib/pdf/fill-eoi-form.ts — load + fill helpers, EOI_TEMPLATE_PDF_PATH
  env override
- assets/ + README documenting the expected source PDF
- next.config outputFileTracingIncludes so the asset is bundled in the
  standalone build

Tests: 8 new (4 fill-form unit + 2 source-PDF route + 2 fallback);
645/645 green.

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

next.config.ts

@@ -18,6 +18,12 @@ const nextConfig: NextConfig = {
   experimental: {
     typedRoutes: true,
   },
+  outputFileTracingIncludes: {
+    // Bundle the EOI source PDF so the in-app EOI pathway can read it at
+    // runtime in the standalone build. Reading via fs.readFile from
+    // process.cwd() requires the file to be traced explicitly.
+    '/api/v1/document-templates/**': ['./assets/eoi-template.pdf'],
+  },
 };
 
 export default nextConfig;