/clear starts a new session instead of clearing in-place, causing lost input

Bug Description

/clear creates a new session instead of clearing the conversation within the current session. This causes a multi-second delay and any input typed during that window is silently lost.

Steps to Reproduce

1. In an active Claude Code session, type /clear and press Enter
2. Immediately start typing your next prompt
3. ~5 seconds later, the CLI transitions to a new session
4. Any text typed during that window is lost

Expected Behavior

/clear should clear the conversation history within the same session — no new session creation. Just reset the conversation context and let the user keep typing. The CLI should handle the clear in-place.

Actual Behavior

/clear triggers a full new session creation with a multi-second delay. The terminal still accepts input during the transition, but that input is discarded when the new session loads.

Impact

This trains users to sit and wait after /clear instead of continuing to type, which defeats the purpose of a fast "reset and go" workflow. Users lose typed input with no warning.