Shell snapshot injected as user message, blocking conversation

Bug Report

Summary: When Claude Code takes a shell snapshot at session start, the command (e.g. source /path/to/.venv/bin/activate) gets injected into the conversation as if it were a user message. Claude responds to it as a real message and waits for user input, blocking ongoing work.

Steps to reproduce:

1. Have a Python virtualenv active in the terminal when opening Claude Code
2. Claude Code takes a shell snapshot capturing the venv activation command
3. The source ...activate command appears as a user message in the conversation
4. Claude responds to it as a real instruction and stops working, waiting for input

Expected behavior: Shell snapshots should never appear as user messages in the conversation.

Actual behavior: Claude responds to the snapshot as if it were a user instruction, blocking the session until the user manually tells Claude to continue.

Additional context: This has happened repeatedly across multiple sessions. The command source /Users/.../Sites/HeroicGuitar/.venv/bin/activate appears injected as a user message, causing Claude to pause and respond to it instead of continuing the task at hand.

Environment: macOS, zsh, oh-my-zsh