chore(release): v2.1.112

Sync all English tutorials with Claude Code v2.1.112 and the new Opus 4.7
model (claude-opus-4-7). Introduces the xhigh effort level (new default on
Opus 4.7), two new built-in slash commands (/ultrareview,
/less-permission-prompts), auto mode without --enable-auto-mode for Max
subscribers on Opus 4.7, PowerShell tool on Windows, Auto-match-terminal
theme, and plan files named after prompts. All 18 EN doc footers bumped to
Claude Code v2.1.112.

Version callouts in README.md, zh/README.md, and uk/README.md updated to
v2.1.112. Changelog entry prepended.

Repo version now tracks Claude Code version (2.3.0 → 2.1.112 is intentional
per new convention).

08-checkpoints/README.md

@@ -315,8 +315,11 @@ Key benefits:
 Remember: checkpoints are not a replacement for git. Use checkpoints for rapid experimentation and git for permanent code changes.
 
 ---
+
 **Last Updated**: April 16, 2026
-**Claude Code Version**: 2.1.110
+**Claude Code Version**: 2.1.112
 **Sources**:
-- https://code.claude.com/docs/en/checkpointing
-**Compatible Models**: Claude Sonnet 4.6, Claude Opus 4.6, Claude Haiku 4.5
+- https://docs.anthropic.com/en/docs/claude-code/checkpointing
+- https://www.anthropic.com/news/claude-opus-4-7
+- https://support.claude.com/en/articles/12138966-release-notes
+**Compatible Models**: Claude Sonnet 4.6, Claude Opus 4.7, Claude Haiku 4.5