fix(chat): Reduce maxToolResponseSize from 800K to 200K

[jguoamz]

Problem

• Large repo can cause result of listDirectory to contain more than 500K characters

Solution

• Reduce maxToolResponseSize from 800K to 200K
• Updated fsRead to read every 4000 lines if the file is too big
• Updated fsWrite to include explanation optional parameter

---

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[github-actions]

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