docs: Sync all tutorials and references with Claude Code v2.1.84

- Slash commands: update to 55+ built-in, add 5 bundled skills, mark 3 deprecated
- Memory: add managed drop-ins (v2.1.83), subagent memory, settings hierarchy
- Skills: add effort, shell frontmatter fields and discovery behavior
- Subagents: add effort, initialPrompt, disallowedTools fields; document Bash agent
- MCP: add WebSocket transport, elicitation, 2KB tool cap, server deduplication
- Hooks: expand from 18 to 25 events, add agent hook type (now 4 types)
- Plugins: add LSP support, userConfig, CLAUDE_PLUGIN_DATA, CLI commands
- Advanced: add Auto Mode, Channels, Voice Dictation, auto permission mode
- CLI: add 17+ new flags, 17 environment variables, new commands
- Update all reference docs (CATALOG, QUICK_REFERENCE, LEARNING-ROADMAP, INDEX)
- Fix stale quiz questions (hook count, permission modes, hook types)

08-checkpoints/README.md

@@ -33,11 +33,14 @@ You can access and manage checkpoints in two primary ways:
 Press `Esc` twice (`Esc` + `Esc`) to open the checkpoint interface and browse saved checkpoints.
 
 ### Using Slash Command
-Use the `/rewind` command for quick access:
+Use the `/rewind` command (alias: `/checkpoint`) for quick access:
 
 ```bash
 # Open rewind interface
 /rewind
+
+# Or use the alias
+/checkpoint
 ```
 
 ## Rewind Options
@@ -274,6 +277,7 @@ Use both together:
 
 - **`Esc` + `Esc`** - Open checkpoint browser
 - **`/rewind`** - Alternative way to access checkpoints
+- **`/checkpoint`** - Alias for `/rewind`
 
 ## Related Concepts