Feat/agentlair integration

[Mallikharjuna Mulpuri (iAbhi001)]

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PR Title

docs: add integration page for langchain-agentlair tool

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PR Description

Link to Issue

Closes # 3428

Summary

This PR adds a new documentation page for the langchain-agentlair package.
AgentLair provides a persistent identity layer for LangChain agents, granting them a stable @agentlair.dev email address, an encrypted cross-session vault, and an immutable audit trail.

Key features documented:

• Persistent Identity: Agents maintain a unique email address across sessions.
• State Management: Encrypted VaultStore and VaultGet tools for secret persistence.
• Auditability: LogObservationTool and AgentLairCallbackHandler for immutable activity logging.
• Tooling: Includes 5 BaseTool subclasses (SendEmail, CheckInbox, VaultStore, VaultGet, LogObservation).

Package Details

• PyPI: [langchain-agentlair](https://www.google.com/search?q=https://pypi.org/project/langchain-agentlair/) (Pending/Live)
• GitHub: https://github.com/piiiico/agentlair-langchain-integration
• Integration Type: Python Tools

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Checklist

(Make sure to check these boxes in the GitHub UI)

• Description: I have added a description of my changes.
• Documentation: I have updated the documentation accordingly.
• Prerequisites: My package is/will be available on PyPI before merging.
• Standardization: All tools are BaseTool subclasses with args_schema (Pydantic v2).

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Files Changed (Verification)

Before you click "Create Pull Request," verify your PR shows exactly these two files:

1. src/oss/python/integrations/tools/agentlair.mdx (The content we drafted)
2. src/docs.json (The sidebar navigation change)

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