Add session/user context to tool calls

[kashifpk]

Description

Add session and user context to tool calls so stateful MCP servers can isolate data per user.

Tasks

• Generate unique session_id for each conversation
• Accept user_id from UI connection (or generate if anonymous)
• Create context object with session_id and user_id
• Include context in all tool call requests to Armory
• Pass context through MCP protocol

Context Structure

{
    "session_id": "sess_abc123",
    "user_id": "user_456",
    "created_at": "2024-01-15T10:30:00Z"
}

Acceptance Criteria

• Each conversation has unique session_id
• User context flows through to Armory
• Context is included in MCP tool invocations

[kashifpk]

Moved to Post-MVP phase - will implement when stateful MCP servers are added.