Add configuration option to control default expand/collapse state of tool output blocks

Feature Description

Add a configuration option to control whether tool output blocks (thinking blocks, context blocks) are expanded or collapsed by default in the terminal UI.

Currently in v0.26.24+, these blocks are collapsed by default to prevent "streaming flicker" and keep the UI clean. While this is a good default, some users prefer to see the full output without manually toggling with Ctrl+O each time.

Proposed solution:

• Add a defaultExpandOutput boolean option to ~/.commandcode/config.json
• Default value: false (current behavior)
• When set to true, tool output blocks would be expanded by default

Use Case

This would benefit users who:

• Need to see the full AI reasoning/context for debugging or learning purposes
• Work in environments where manually expanding blocks adds friction to their workflow
• Prefer transparency in AI interactions and want to review all outputs
• Are reviewing complex multi-step operations where collapsing hides important context

Additional Context

This is a feature request stemming from the v0.26.24 release which intentionally collapsed these blocks by default. The current workaround is using Ctrl+O to toggle, but a configuration option would provide flexibility without requiring action on every session.

Priority: Important for my workflow

先找出 ~/.commandcode/config.json 的設定處理邏輯，以及控制工具輸出區塊和 Ctrl+O 切換的終端 UI 進入點。在保留目前預設折疊狀態的同時，加入 defaultExpandOutput 行為，然後確認將其設定為 true 會以展開 thinking 區塊和內容區塊的狀態啟動工作階段。