Add native Claude Code / Codex adapters

[ding-swj]

AgentScope currently supports Generic JSONL and permissive Session JSON imports. The next step is native adapters for Claude Code and Codex session exports.

Goals:

• Collect small anonymized Claude Code and Codex session samples
• Map native tool names to AgentScope action types
• Preserve file reads, edits, commands, test results, and summaries
• Add fixtures and CLI tests for each adapter
• Document supported input shapes and limitations

Non-goals:

• Scraping private IDE data
• Reconstructing hidden model reasoning
• Calling external services