📝 Add docstrings to qa

Docstrings generation was requested by @KambleSahil3.

* #1286 (comment)

The following files were modified:

* `apps/api-gateway/src/main.ts`
* `libs/common/src/custom-overrideable-validation-pipe.ts`
* `libs/prisma-service/prisma/scripts/update_client_credential_data.sh`

Author: coderabbitai[bot]

apps/api-gateway/src/main.ts

@@ -17,6 +17,11 @@ import { NatsInterceptor } from '@credebl/common';
 import { UpdatableValidationPipe } from '@credebl/common/custom-overrideable-validation-pipe';
 dotenv.config();
 
+/**
+ * Bootstraps and starts the NestJS API Gateway application with microservice integration, middleware, API documentation, security, and global configuration.
+ *
+ * Initializes the application, connects to a NATS microservice, sets up middleware for request parsing and URL validation, configures Swagger API documentation, applies global exception filters, enables CORS based on environment configuration, serves static files, applies a custom global validation pipe, enables security middleware, and starts listening on the configured host and port.
+ */
 async function bootstrap(): Promise<void> {
   const app = await NestFactory.create(AppModule);
 

libs/common/src/custom-overrideable-validation-pipe.ts

@@ -18,7 +18,13 @@ import { Reflector } from '@nestjs/core';
 
 export const REWRITE_VALIDATION_OPTIONS = 'rewrite_validation_options';
 
-// eslint-disable-next-line @typescript-eslint/explicit-function-return-type
+/**
+ * Decorator that overrides global validation options for a specific route handler or controller.
+ *
+ * Attaches custom {@link ValidatorOptions} metadata, allowing selective adjustment of validation behavior such as whitelisting or property checks on a per-handler or per-class basis.
+ *
+ * @param options - The validation options to apply for the decorated handler or class.
+ */
 export function RewriteValidationOptions(options: ValidatorOptions) {
   return SetMetadata(REWRITE_VALIDATION_OPTIONS, options);
 }

libs/prisma-service/prisma/scripts/update_client_credential_data.sh

@@ -5,7 +5,20 @@ DB_URL=$1
 CLIENT_ID=$2
 CLIENT_SECRET=$3
 
-# Function to update clientId and clientSecret
+# Updates the clientId and clientSecret fields in the "user" table where both are NULL.
+#
+# Globals:
+#   DB_URL: The database connection URL.
+#   CLIENT_ID: The new clientId value to set.
+#   CLIENT_SECRET: The new clientSecret value to set.
+#
+# Outputs:
+#   Prints the result of the SQL update operation to STDOUT, including success or failure messages.
+#
+# Example:
+#
+#   update_client_credentials
+#   # Updates all users with NULL clientId and clientSecret, setting them to the provided values.
 update_client_credentials() {
     local update_query="UPDATE \"user\" SET \"clientId\" = '${CLIENT_ID}', \"clientSecret\" = '${CLIENT_SECRET}' WHERE \"clientId\" IS NULL AND \"clientSecret\" IS NULL;"