[FEATURE] Send messages to running agents without stopping them

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Basically just https://github.com/anthropics/claude-code/issues/5974, but not closed. That issue was closed and locked because it was inactive, then every future request of the same thing has been closed as duplicates of it:

• https://github.com/anthropics/claude-code/issues/21419
• https://github.com/anthropics/claude-code/issues/13431

Proposed Solution

Unlock the old issue or don't mark all new issues of the same problem as duplicates of a closed and locked issue, when it was just locked because it was stale!

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

_No response_

Additional Context

_No response_