fix(email): preserve personalization tokens for template rendering

packages/blocks/src/variables.ts

@@ -27,9 +27,11 @@ export function resolveDocumentVariables(
   document: BlockDocument,
   catalog: Record<string, "string" | "number" | "date" | "boolean">,
   data: Record<string, unknown> = {},
-  options: { requireValues?: boolean } = {},
+  options: { requireValues?: boolean; preserveTokens?: boolean } = {},
 ): Result<BlockDocument> {
   const diagnostics: Diagnostic[] = [];
+  if (options.preserveTokens && options.requireValues)
+    return { ok: false, errors: [{ code: "variable.mode", message: "Template tokens cannot be preserved when resolved values are required.", severity: "error" }] };
   const visit = (value: JsonValue, path: string): JsonValue => {
     if (typeof value === "string")
       return value.replace(TOKEN, (raw, key: string, fallback: string | undefined) => {
@@ -38,6 +40,7 @@ export function resolveDocumentVariables(
           diagnostics.push({ code: "variable.unknown", message: `Unknown variable ${key}.`, severity: "error", path });
           return raw;
         }
+        if (options.preserveTokens) return raw;
         const supplied = data[key];
         if (supplied === undefined || supplied === null || supplied === "") {
           if (fallback !== undefined) return fallback.trim();