Claude Code 2.1.88 fixes flicker, crashes

These are the releases that matter once a CLI moves from demoware to daily driver: they remove the papercuts that break trust. The headline features are small, but the reliability work is what will actually keep developers in the tool.

• –`CLAUDE_CODE_NO_FLICKER=1` and the alt-screen rendering change target the kind of UI instability that makes terminal agents feel brittle during long runs.
• –The new `PermissionDenied` hook gives integrations a cleaner recovery path when auto-mode classifier denials happen, instead of forcing a hard stop.
• –Prompt cache, `StructuredOutput`, and nested `CLAUDE.md` fixes point to a push toward more predictable long-session behavior and fewer wasted tokens.
• –Windows CRLF handling, PowerShell quirks, and `--resume` crash fixes make the CLI more credible outside the happy-path macOS/Linux workflow.
• –The memory leak and large-file OOM fixes suggest Anthropic is seeing real scale pressure from serious repos, not just toy examples.