fix: add keyv as direct dependency (#154)

keyv is a transitive dependency of Baileys via @cacheable/utils,
but since Baileys is in optionalDependencies, some npm versions
don't properly install its transitive dependencies on fresh installs.

Adding keyv as a direct dependency ensures it's always installed.

Fixes ERR_MODULE_NOT_FOUND: Cannot find package 'keyv' on fresh installs.

Written by Cameron ◯ Letta Code

"The best time to fix a dependency bug is before someone reports it.
The second best time is immediately after." - Ancient npm proverb

package-lock.json

@@ -21,6 +21,7 @@
         "googleapis": "^170.1.0",
         "grammy": "^1.39.3",
         "gray-matter": "^4.0.3",
+        "keyv": "^5.6.0",
         "node-schedule": "^2.1.1",
         "open": "^11.0.0",
         "openai": "^6.17.0",
@@ -1268,8 +1269,7 @@
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/@keyv/serialize/-/serialize-1.1.1.tgz",
       "integrity": "sha512-dXn3FZhPv0US+7dtJsIi2R+c7qWYiReoEh5zUntWCf4oSpMNib8FDhSoed6m3QyZdx5hK7iLFkYk3rNxwt8vTA==",
-      "license": "MIT",
-      "optional": true
+      "license": "MIT"
     },
     "node_modules/@letta-ai/letta-client": {
       "version": "1.7.7",
@@ -4811,7 +4811,6 @@
       "resolved": "https://registry.npmjs.org/keyv/-/keyv-5.6.0.tgz",
       "integrity": "sha512-CYDD3SOtsHtyXeEORYRx2qBtpDJFjRTGXUtmNEMGyzYOKj1TE3tycdlho7kA1Ufx9OYWZzg52QFBGALTirzDSw==",
       "license": "MIT",
-      "optional": true,
       "dependencies": {
         "@keyv/serialize": "^1.1.1"
       }