Claude Code Plugin Fixes and Bedrock Log Growth Bugs

We break down a validation failure that blocked old Claude Code plugin imports in Codex CLI 0.142.x, plus the 0.143.0-alpha parser fix and a quick cache-file workaround for affected users.

Then we cover MCP tool search defaults, the new respect_system_proxy setting for macOS enterprise networks, and a Bedrock streaming bug that bloats .jsonl session logs while skewing token counts.