docs: sync to Claude Code v2.1.170 (#140)

* docs: sync to Claude Code v2.1.170

Additive sync covering features shipped in v2.1.161-2.1.170. No breaking
changes in the window.

- 10-cli: add Claude Fable 5 model row (claude-fable-5); --safe-mode flag
  + CLAUDE_CODE_SAFE_MODE / CLAUDE_CODE_DISABLE_BUNDLED_SKILLS env vars;
  note --fallback-model now applies to interactive sessions (v2.1.166)
- 01-slash-commands: document /cd (preserves prompt cache, v2.1.169)
- 03-skills: document disableBundledSkills setting + env var (v2.1.169)
- 07-plugins: document /plugin list --enabled/--disabled (v2.1.163)
- 06-hooks: document Stop/SubagentStop additionalContext return (v2.1.163)
- 09-advanced-features: add Safe Mode + fallbackModel subsections
- 05-mcp: stdio servers receive CLAUDE_CODE_SESSION_ID on --resume (v2.1.161);
  add metadata footer (none existed)
- refresh footers on all edited files to 2.1.170 / June 10, 2026

* fix(mcp): correct CLAUDE_CODE_SESSION_ID --resume version to 2.1.163

07-plugins/README.md

@@ -736,6 +736,14 @@ claude plugin install plugin-name@marketplace-name
 /plugin disable plugin-name
 ```
 
+### Listing installed plugins (v2.1.163)
+Confirm which plugins are active in the current session:
+```bash
+/plugin list             # all installed plugins
+/plugin list --enabled   # only enabled plugins
+/plugin list --disabled  # only disabled plugins
+```
+
 ### Local Plugin (for development)
 ```bash
 # CLI flag for local testing (repeatable for multiple plugins)
@@ -1107,10 +1115,11 @@ The following Claude Code features work together with plugins:
 
 ---
 
-**Last Updated**: June 2, 2026
-**Claude Code Version**: 2.1.160
+**Last Updated**: June 10, 2026
+**Claude Code Version**: 2.1.170
 **Sources**:
 - https://code.claude.com/docs/en/plugins
+- https://code.claude.com/docs/en/slash-commands
 - https://code.claude.com/docs/en/plugin-marketplaces
 - https://github.com/anthropics/claude-code/releases/tag/v2.1.117
 - https://github.com/anthropics/claude-code/releases/tag/v2.1.118