feat: add integration tests (#6923)

### Summary

This PR introduces several integration tests, a mix of manually written
tests and those generated using the `generate-integration-tests` Python
script located in the `scripts` folder.

### Tests Added:
- **Authentication tests**: Validating login, registration, and token
handling.
- **FindMany queries**: Fetching multiple records for all existing
entities that do not require input arguments.

### How the Integration Tests Work:
- A `setupTest` function is called during the Jest test run. This
function initializes a test instance of the application and exposes it
on a dedicated port.
- Since tests are executed in isolated workers, they do not have direct
access to the in-memory app instance. Instead, the tests query the
application through the exposed port.
- A static accessToken is used, this one as a big expiration time so it
will never expire (365 years)
- The queries are executed, and the results are validated against
expected outcomes.

### Current State and Next Steps:
- These tests currently run using the existing development seed data. We
plan to introduce more comprehensive test data using `faker` to improve
coverage.
- At the moment, the only mutation tests implemented are for
authentication. Future updates should include broader mutation testing
for other entities.

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/scripts/generate-integration-tests/introspection-query.ts

@@ -0,0 +1,89 @@
+export const INTROSPECTION_QUERY = `
+query IntrospectionQuery {
+  __schema {
+    queryType { name }
+    mutationType { name }
+    subscriptionType { name }
+    types {
+      ...FullType
+    }
+    directives {
+      name
+      description
+      locations
+      args {
+        ...InputValue
+      }
+    }
+  }
+}
+
+fragment FullType on __Type {
+  kind
+  name
+  description
+  fields(includeDeprecated: true) {
+    name
+    description
+    args {
+      ...InputValue
+    }
+    type {
+      ...TypeRef
+    }
+    isDeprecated
+    deprecationReason
+  }
+  inputFields {
+    ...InputValue
+  }
+  interfaces {
+    ...TypeRef
+  }
+  enumValues(includeDeprecated: true) {
+    name
+    description
+    isDeprecated
+    deprecationReason
+  }
+  possibleTypes {
+    ...TypeRef
+  }
+}
+
+fragment InputValue on __InputValue {
+  name
+  description
+  type { ...TypeRef }
+  defaultValue
+}
+
+fragment TypeRef on __Type {
+  kind
+  name
+  ofType {
+    kind
+    name
+    ofType {
+      kind
+      name
+      ofType {
+        kind
+        name
+        ofType {
+          kind
+          name
+          ofType {
+            kind
+            name
+            ofType {
+              kind
+              name
+            }
+          }
+        }
+      }
+    }
+  }
+}
+`;