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>

assets/README.md

@@ -0,0 +1,48 @@
+# `assets/`
+
+Server-side runtime assets bundled by Next.js (via `outputFileTracingIncludes`
+in `next.config.ts`). These files are read with `fs.readFile` from
+`process.cwd()` at runtime, so they are NOT served as public URLs — use
+`public/` for that.
+
+## `eoi-template.pdf`
+
+The source PDF used by the in-app EOI generation pathway
+(`src/lib/pdf/fill-eoi-form.ts`). It must be the **same** PDF that the
+Documenso EOI template uploads, so both pathways produce equivalent
+documents.
+
+The PDF must contain AcroForm fields with these exact names (mirroring the
+Documenso template's `formValues` keys — see
+`docs/eoi-documenso-field-mapping.md`):
+
+| Field name     | Type     | Filled with                                           |
+| -------------- | -------- | ----------------------------------------------------- |
+| `Name`         | Text     | `EoiContext.client.fullName`                          |
+| `Email`        | Text     | `EoiContext.client.primaryEmail`                      |
+| `Address`      | Text     | `street, city, country`                               |
+| `Yacht Name`   | Text     | `EoiContext.yacht.name`                               |
+| `Length`       | Text     | `EoiContext.yacht.lengthFt`                           |
+| `Width`        | Text     | `EoiContext.yacht.widthFt`                            |
+| `Draft`        | Text     | `EoiContext.yacht.draftFt`                            |
+| `Berth Number` | Text     | `EoiContext.berth.mooringNumber`                      |
+| `Lease_10`     | Checkbox | always `false` (legacy default — Purchase, not Lease) |
+| `Purchase`     | Checkbox | always `true`                                         |
+
+Form fields stay interactive after generation (not flattened), so the
+recipient can still tweak values before signing if the in-app pathway is
+followed by a Documenso send.
+
+### Override path
+
+In dev/test, set `EOI_TEMPLATE_PDF_PATH=/abs/path/to/your/template.pdf` to
+point at a different file (e.g. a fixture).
+
+### How to extract this PDF
+
+The legacy flow uploads this PDF to Documenso template ID 8. To get the
+exact bytes:
+
+1. In Documenso, open the EOI template.
+2. Download the source PDF.
+3. Drop it here as `eoi-template.pdf`.