fix(05-04): pre-select document client and add manual email entry

- PreparePanel now receives separate assignedClientId (nullable) and
  defaultClientId props so it can distinguish an explicitly locked
  client from just a default
- When document already has assignedClientId: show locked read-only
  display; user cannot change the primary recipient
- When document has no assignedClientId: default to document owner in
  dropdown but allow changing; option to clear and enter email manually
- Added textarea for additional/CC email addresses (comma or newline
  separated) that is always visible for either mode
- POST /api/documents/[id]/prepare now accepts and stores emailAddresses
  array alongside assignedClientId
- Added email_addresses jsonb column to documents table via migration
  0004_military_maximus.sql

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

teressa-copeland-homes/src/app/api/documents/[id]/prepare/route.ts

@@ -18,6 +18,8 @@ export async function POST(
   const body = await req.json() as {
     textFillData?: Record<string, string>;
     assignedClientId?: string;
+    /** Email addresses to send the document to (client email + any CC addresses). */
+    emailAddresses?: string[];
   };
 
   const doc = await db.query.documents.findFirst({ where: eq(documents.id, id) });
@@ -45,6 +47,7 @@ export async function POST(
       preparedFilePath: preparedRelPath,
       textFillData: body.textFillData ?? null,
       assignedClientId: body.assignedClientId ?? doc.assignedClientId ?? null,
+      emailAddresses: body.emailAddresses ?? null,
       status: 'Sent',
       sentAt: new Date(),
     })