The hermes-agent CLI KawaiiSpinner sends decorative kaomoji text
like "(◕‿◕✿) pondering..." through thinking_callback for its TUI
widget. The bridge forwarded this as thinking.delta events, which
the frontend stored in the message reasoning field.
Over long conversations this contaminated the model's context:
_copy_reasoning_content_for_api promoted the kaomoji text to
reasoning_content, causing the LLM to reproduce kaomoji patterns
in a self-reinforcing degradation loop.
Fix: _make_thinking_callback unconditionally sends empty text.
thinking_callback is purely CLI spinner status — it has no place in
conversation history. Actual model reasoning (reasoning.delta) is
unaffected.
