feat(lasso): Upgrade to Lasso API v3 and fix ULID generation (#15941)

* 1. add v3 classify
2. add new classifix for masking
3. support same id for the conversation for pre and post
working with duplicates

* clean code, remove some debug and run tests

* update liter errors

* improvment for Code Organization, httpx Error Handling Specificity, Logging Improvements and Type

* transfer test test_lasso_guard_config to the new location

* Fix type hints and linting errors in lasso.py

- Add type: ignore for httpx module when None
- Fix return type issues in _handle_classification and _handle_masking
- Ensure masked_messages is not None before passing to _apply_masking_to_model_response
- Convert LassoResponse to dict for _log_masking_applied call

* feat(lasso): Upgrade to Lasso API v3 and fix ULID generation

- Update Lasso API endpoints from v2 to v3 (/gateway/v3/classify)
- Update masking endpoints from v1 to v3 (/gateway/v3/classifix)
- Fix ULID generation: use ulid.new() instead of ULID() constructor
- Resolve MemoryView error that occurred with incorrect ULID usage

Tested with real proxy server and verified:
- Malicious content (jailbreak) properly blocked
- Safe content passes through guardrail
- PII detection and masking works correctly
- No ULID generation errors

* docs(lasso): Add ulid-py>=1.1.0 dependency prerequisite

Add Prerequisites section documenting the required ulid-py package
(version 1.1.0 or higher) for Lasso guardrail conversation tracking.

* update docs with the right api_key format

docs/my-website/docs/proxy/guardrails/lasso_security.md

@@ -6,6 +6,16 @@ import TabItem from '@theme/TabItem';
 
 Use [Lasso Security](https://www.lasso.security/) to protect your LLM applications from prompt injection attacks, harmful content generation, and other security threats through comprehensive input and output validation.
 
+## Prerequisites
+
+The Lasso guardrail requires the `ulid-py` package (version 1.1.0 or higher) for generating unique conversation identifiers:
+
+```shell
+pip install ulid-py>=1.1.0
+```
+
+This package is used to create lexicographically sortable identifiers for tracking conversations and sessions in the Lasso Security platform.
+
 ## Quick Start
 
 ### 1. Define Guardrails on your LiteLLM config.yaml 
@@ -25,7 +35,7 @@ guardrails:
       guardrail: lasso
       mode: "pre_call"
       api_key: os.environ/LASSO_API_KEY
-      api_base: "https://server.lasso.security/gateway/v3/classify"  # Optional: defaults to v3 endpoint
+      api_base: "https://server.lasso.security"
   - guardrail_name: "lasso-post-guard"
     litellm_params:
       guardrail: lasso

litellm/proxy/guardrails/guardrail_hooks/lasso/lasso.py

@@ -10,10 +10,11 @@ import uuid
 from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Type, Union, TypedDict
 
 try:
-    from ulid import ULID
+    import ulid
 
     ULID_AVAILABLE = True
 except ImportError:
+    ulid = None  # type: ignore
     ULID_AVAILABLE = False
 
 try:
@@ -114,8 +115,8 @@ class LassoGuardrail(CustomGuardrail):
         Generate a ULID (Universally Unique Lexicographically Sortable Identifier).
         Falls back to UUID if ULID library is not available.
         """
-        if ULID_AVAILABLE:
-            return str(ULID())  # type: ignore
+        if ULID_AVAILABLE and ulid is not None:
+            return str(ulid.new())  # type: ignore
         else:
             verbose_proxy_logger.debug("ULID library not available, using UUID")
             return str(uuid.uuid4())
@@ -222,7 +223,7 @@ class LassoGuardrail(CustomGuardrail):
                 if self.mask:
                     headers = self._prepare_headers(response_data)
                     payload = self._prepare_payload(response_messages, "COMPLETION", response_data)
-                    api_url = f"{self.api_base}/gateway/v1/classifix"
+                    api_url = f"{self.api_base}/gateway/v3/classifix"
 
                     try:
                         lasso_response = await self._call_lasso_api(headers=headers, payload=payload, api_url=api_url)
@@ -370,7 +371,7 @@ class LassoGuardrail(CustomGuardrail):
         try:
             headers = self._prepare_headers(data, cache)
             payload = self._prepare_payload(messages, message_type, data, cache)
-            api_url = f"{self.api_base}/gateway/v1/classifix"
+            api_url = f"{self.api_base}/gateway/v3/classifix"
             response = await self._call_lasso_api(headers=headers, payload=payload, api_url=api_url)
             self._process_lasso_response(response)
 
@@ -513,7 +514,7 @@ class LassoGuardrail(CustomGuardrail):
         api_url: Optional[str] = None,
     ) -> LassoResponse:
         """Call the Lasso API and return the response."""
-        url = api_url or f"{self.api_base}/gateway/v2/classify"
+        url = api_url or f"{self.api_base}/gateway/v3/classify"
         verbose_proxy_logger.debug(f"Calling Lasso API with messageType: {payload.get('messageType')}")
         response = await self.async_handler.post(
             url=url,