fix: Correct urlId format for documents (10 chars)

Outline uses 10-char alphanumeric urlId, not 21-char hex.
Documents with wrong format returned 404 "Not found".

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tools/documents.ts

@@ -248,7 +248,7 @@ const createDocument: BaseTool<CreateDocumentArgs> = {
           )
           VALUES (
             gen_random_uuid(),
-            substring(replace(gen_random_uuid()::text, '-', '') from 1 for 21),
+            substring(md5(random()::text) from 1 for 10),
             $1, $2, $3, $4, $5, $6, $7, $8, $9, NOW(), NOW(), 1, false, false, false
           )
           RETURNING id, "urlId", title, "collectionId", "publishedAt", "createdAt"