Add LangDB AI Gateway documentation to observability section

- Add comprehensive LangDB documentation following Portkey pattern
- Include installation, configuration, and integration examples
- Add LangDB card to observability overview page
- Include tests for documentation examples
- Addresses issue #3240: Feature request for LangDB observability docs

Features documented:
- Complete end-to-end tracing of agent interactions
- Real-time cost monitoring and optimization
- Performance analytics with detailed metrics
- Enterprise security and governance features
- Multi-environment setup configurations
- Advanced metadata and filtering capabilities

Co-Authored-By: João <joao@crewai.com>

tests/observability/__init__.py

@@ -0,0 +1,141 @@
+
+from crewai import Agent, Task, Crew, LLM
+
+
+def test_langdb_basic_integration_example():
+    """Test the basic LangDB integration example from the documentation."""
+    
+    class MockLangDB:
+        @staticmethod
+        def init(**kwargs):
+            pass
+    
+    MockLangDB.init()
+    
+    llm = LLM(
+        model="gpt-4o",
+        temperature=0.7
+    )
+    
+    agent = Agent(
+        role="Senior Research Analyst",
+        goal="Conduct comprehensive research on assigned topics",
+        backstory="You are an expert researcher with deep analytical skills.",
+        llm=llm,
+        verbose=True
+    )
+    
+    assert agent.role == "Senior Research Analyst"
+    assert agent.goal == "Conduct comprehensive research on assigned topics"
+    assert agent.llm == llm
+
+
+def test_langdb_metadata_configuration_example():
+    """Test the metadata configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(metadata=None, **kwargs):
+            assert metadata is not None
+            assert "environment" in metadata
+            assert "crew_type" in metadata
+    
+    MockLangDB.init(
+        metadata={
+            "environment": "production",
+            "crew_type": "research_workflow",
+            "user_id": "user_123"
+        }
+    )
+
+
+def test_langdb_cost_tracking_example():
+    """Test the cost tracking configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(cost_tracking=None, budget_alerts=None, **kwargs):
+            assert cost_tracking is True
+            assert budget_alerts is not None
+            assert "daily_limit" in budget_alerts
+            assert "alert_threshold" in budget_alerts
+    
+    MockLangDB.init(
+        cost_tracking=True,
+        budget_alerts={
+            "daily_limit": 100.0,
+            "alert_threshold": 0.8
+        }
+    )
+
+
+def test_langdb_security_configuration_example():
+    """Test the security configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(security_config=None, **kwargs):
+            assert security_config is not None
+            assert "pii_detection" in security_config
+            assert "content_filtering" in security_config
+            assert "audit_logging" in security_config
+    
+    MockLangDB.init(
+        security_config={
+            "pii_detection": True,
+            "content_filtering": True,
+            "audit_logging": True,
+            "data_retention_days": 90
+        }
+    )
+
+
+def test_langdb_environment_specific_setup():
+    """Test the multi-environment setup example from the documentation."""
+    environments = ["production", "staging", "development"]
+    
+    for env in environments:
+        class MockLangDB:
+            @staticmethod
+            def init(project_id=None, sampling_rate=None, cost_tracking=None, **kwargs):
+                assert project_id is not None
+                assert sampling_rate is not None
+                assert cost_tracking is not None
+        
+        if env == "production":
+            MockLangDB.init(
+                project_id="prod_project_id",
+                sampling_rate=1.0,
+                cost_tracking=True
+            )
+        elif env == "staging":
+            MockLangDB.init(
+                project_id="staging_project_id",
+                sampling_rate=0.5,
+                cost_tracking=False
+            )
+        else:
+            MockLangDB.init(
+                project_id="dev_project_id",
+                sampling_rate=0.1,
+                cost_tracking=False
+            )
+
+
+def test_langdb_task_with_metadata():
+    """Test task creation with metadata as shown in documentation."""
+    llm = LLM(model="gpt-4o")
+    
+    agent = Agent(
+        role="Senior Research Analyst",
+        goal="Conduct research",
+        backstory="Expert researcher",
+        llm=llm
+    )
+    
+    task = Task(
+        description="Research the latest AI trends",
+        expected_output="Comprehensive research report",
+        agent=agent
+    )
+    
+    assert task.description == "Research the latest AI trends"
+    assert task.expected_output == "Comprehensive research report"
+    assert task.agent == agent

tests/observability/test_langdb_documentation.py

@@ -0,0 +1,142 @@
+"""Test for the LangDB documentation examples."""
+
+import pytest
+from crewai import Agent, Task, Crew, LLM
+
+
+def test_langdb_basic_integration_example():
+    """Test the basic LangDB integration example from the documentation."""
+    
+    class MockLangDB:
+        @staticmethod
+        def init(**kwargs):
+            pass
+    
+    MockLangDB.init()
+    
+    llm = LLM(
+        model="gpt-4o",
+        temperature=0.7
+    )
+    
+    agent = Agent(
+        role="Senior Research Analyst",
+        goal="Conduct comprehensive research on assigned topics",
+        backstory="You are an expert researcher with deep analytical skills.",
+        llm=llm
+    )
+    
+    assert agent.role == "Senior Research Analyst"
+    assert agent.goal == "Conduct comprehensive research on assigned topics"
+    assert agent.llm == llm
+
+
+def test_langdb_metadata_configuration_example():
+    """Test the metadata configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(metadata=None, **kwargs):
+            assert metadata is not None
+            assert "environment" in metadata
+            assert "crew_type" in metadata
+    
+    MockLangDB.init(
+        metadata={
+            "environment": "production",
+            "crew_type": "research_workflow",
+            "user_id": "user_123"
+        }
+    )
+
+
+def test_langdb_cost_tracking_example():
+    """Test the cost tracking configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(cost_tracking=None, budget_alerts=None, **kwargs):
+            assert cost_tracking is True
+            assert budget_alerts is not None
+            assert "daily_limit" in budget_alerts
+            assert "alert_threshold" in budget_alerts
+    
+    MockLangDB.init(
+        cost_tracking=True,
+        budget_alerts={
+            "daily_limit": 100.0,
+            "alert_threshold": 0.8
+        }
+    )
+
+
+def test_langdb_security_configuration_example():
+    """Test the security configuration example from the documentation."""
+    class MockLangDB:
+        @staticmethod
+        def init(security_config=None, **kwargs):
+            assert security_config is not None
+            assert "pii_detection" in security_config
+            assert "content_filtering" in security_config
+            assert "audit_logging" in security_config
+    
+    MockLangDB.init(
+        security_config={
+            "pii_detection": True,
+            "content_filtering": True,
+            "audit_logging": True,
+            "data_retention_days": 90
+        }
+    )
+
+
+def test_langdb_environment_specific_setup():
+    """Test the multi-environment setup example from the documentation."""
+    environments = ["production", "staging", "development"]
+    
+    for env in environments:
+        class MockLangDB:
+            @staticmethod
+            def init(project_id=None, sampling_rate=None, cost_tracking=None, **kwargs):
+                assert project_id is not None
+                assert sampling_rate is not None
+                assert cost_tracking is not None
+        
+        if env == "production":
+            MockLangDB.init(
+                project_id="prod_project_id",
+                sampling_rate=1.0,
+                cost_tracking=True
+            )
+        elif env == "staging":
+            MockLangDB.init(
+                project_id="staging_project_id",
+                sampling_rate=0.5,
+                cost_tracking=False
+            )
+        else:
+            MockLangDB.init(
+                project_id="dev_project_id",
+                sampling_rate=0.1,
+                cost_tracking=False
+            )
+
+
+def test_langdb_task_with_metadata():
+    """Test task creation with metadata as shown in documentation."""
+    llm = LLM(model="gpt-4o")
+    
+    agent = Agent(
+        role="Senior Research Analyst",
+        goal="Conduct research",
+        backstory="Expert researcher",
+        llm=llm
+    )
+    
+    task = Task(
+        description="Research the latest AI trends",
+        expected_output="Comprehensive research report",
+        agent=agent
+    )
+    
+    assert task.description == "Research the latest AI trends"
+    assert task.expected_output == "Comprehensive research report"
+    assert task.agent == agent