feat: more llm provider options (google, mistral) (#28)

* feat: add google provider

* fix: default for google model

* feat: multiple providers

* fix: defaults from env for login form

* fix: add mistral to env files

* chore: delete unused code

* chore: revert database url to original

* fix: render default value for api key from env on server

* fix: type errors during compilation

---------

Co-authored-by: Vasily Zubarev <me@vas3k.ru>

package.json

@@ -10,8 +10,13 @@
     "lint": "next lint"
   },
   "dependencies": {
+    "@dnd-kit/core": "^6.3.1",
+    "@dnd-kit/sortable": "^10.0.0",
     "@fast-csv/format": "^5.0.2",
     "@fast-csv/parse": "^5.0.2",
+    "@langchain/google-genai": "^0.2.14",
+    "@langchain/mistralai": "^0.2.1",
+    "@langchain/openai": "^0.6.1",
     "@prisma/client": "^6.6.0",
     "@radix-ui/react-avatar": "^1.1.3",
     "@radix-ui/react-checkbox": "^1.1.4",
@@ -33,11 +38,11 @@
     "clsx": "^2.1.1",
     "date-fns": "^3.6.0",
     "jszip": "^3.10.1",
+    "langchain": "^0.3.30",
     "lucide-react": "^0.475.0",
     "mime-types": "^3.0.1",
     "next": "^15.2.4",
     "next-themes": "^0.4.4",
-    "openai": "^4.85.4",
     "pdf2pic": "^3.1.4",
     "react": "^19.0.0",
     "react-day-picker": "^8.10.1",