Feature: Allow existing Claude sessions to communicate with each other

Feature Request

Description:
Allow two or more running Claude Code sessions to communicate with each other — sharing context, delegating subtasks, or coordinating work across terminals/windows.

Use case:
When working on complex tasks, I often have multiple Claude sessions open (e.g., one researching, one implementing, one testing). Currently they're completely isolated — there's no way for one session to pass findings, context, or instructions to another running session.

Proposed behavior:

• A mechanism for one session to send a message/context to another active session
• Could be as simple as a named channel, shared memory space, or inter-session messaging protocol
• Would enable workflows like: "research agent finds the answer → sends it to implementation agent" without manual copy-paste

Why this matters:
Multi-session workflows are already common (multiple terminals, IDE + CLI, etc.). Letting sessions talk to each other would unlock proper multi-agent coordination without needing to funnel everything through a single context window.

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Submitted on behalf of a user.