docs: sync to Claude Code v2.1.235 (#174)

* docs: sync to Claude Code v2.1.235

Syncs the tutorial repo from v2.1.233 to v2.1.235, fixes a fabricated
plugin-command reference and a wrong lesson-quiz answer, closes translation
fan-out gaps, and documents six new features from v2.1.234/v2.1.235.

* docs(slash-commands): scope v2.1.234 dialog-command claims to the fullscreen TUI

The v2.1.234 changelog carries two separate entries: /permissions opening
mid-turn unconditionally, and the /add-dir, /autocompact, /theme, /help,
/config and /advisor dialogs opening mid-turn in the fullscreen TUI. The
sync flattened both into one unqualified bullet, so a reader on the default
renderer would find the described behavior absent.

Also corrects the CATALOG usage-limit auto-continue row, which described an
on-by-default feature as opt-in ("Enable via /config"); the changelog says
"turn it off in /config".

* docs(advanced-features): correct spellcheck value shape, default, and scope

settings.md documents `spellcheck` as object-valued
(`{"enabled": true, "language": "en_GB"}`) and read from user settings, the
--settings flag, and managed settings only; interactive-mode.md adds that it
is off by default and needs aspell, hunspell, or ispell on PATH. CATALOG told
readers to set a bare `"spellcheck": true`, and both settings tables sit under
preambles promising project-scope settings work, which for this key they do
not.

Also repoints CATALOG's hook-configuration example at pre-tool-check.sh; the
table rename left the example on validate-bash.py, which is not in 06-hooks/.

* docs(plugins): drop the unsupported claim that /plugin update does not exist

The sync asserted "Updating is CLI-only — there is no `/plugin update` slash
command". The plugins reference contradicts that: it refers to running
`/plugin update` twice in present tense (the cache-key section, and the
explicit-version row that says `/plugin update` reports "already at the
latest version"). The v2.1.235 binary carries no `/plugin update` string and
its own update notices point at `claude plugin update <name>` in a terminal,
so the sources conflict and neither absolute is safe to teach.

Recommends the CLI form on its documented merits instead of asserting a
negative. Mirrored to vi/ja/zh/uk and to the lesson-quiz Q8 explanation,
which taught the same false negative. Q8's correct answer is unchanged.

* docs(advanced-features): complete the v2.1.234 env-var fan-out and 04 TOC (#175)

The env-var block was still headed (v2.1.221-v2.1.233) and omitted both
variables v2.1.234 added: CLAUDE_CODE_PROJECT_DIR_NAME, which had reached
only 10-cli and CATALOG, and CLAUDE_CODE_GOAL_CHECKIN_MINUTES, which was in
prose and a CATALOG row but no env-var table.

Also adds the one missing 04-subagents TOC entry: Additional Resources was
the only H2 without one, leaving the reconciled TOC at 26 of 27 sections.

07-plugins/README.md

@@ -1098,7 +1098,7 @@ Complete PR review workflow with security, testing, and documentation checks.
 
 2. **View plugin details:**
    ```bash
-   /plugin info plugin-name
+   claude plugin details plugin-name
    ```
 
 3. **Install a plugin:**
@@ -1121,13 +1121,17 @@ Complete PR review workflow with security, testing, and documentation checks.
 ### Listing Installed Plugins
 
 ```bash
-/plugin list --installed
+/plugin list             # all installed plugins
+/plugin list --enabled   # only enabled plugins
+/plugin list --disabled  # only disabled plugins
 ```
 
 ### Updating a Plugin
 
+Use the CLI form — it is the one documented under [`plugin update`](https://code.claude.com/docs/en/plugins-reference) and the one Claude Code itself points you to when an update is available:
+
 ```bash
-/plugin update plugin-name
+claude plugin update plugin-name
 ```
 
 ### Disabling/Enabling a Plugin
@@ -1190,7 +1194,7 @@ The following Claude Code features work together with plugins:
 - Verify paths in `plugin.json` match actual directory structure
 - Check file permissions: `chmod +x scripts/`
 - Review component file syntax
-- Check logs: `/plugin debug plugin-name`
+- Check the component inventory: `claude plugin details plugin-name`
 
 ### MCP Connection Failed
 - Verify environment variables are set correctly
@@ -1199,9 +1203,9 @@ The following Claude Code features work together with plugins:
 - Review MCP configuration in `mcp/` directory
 
 ### Commands Not Available After Install
-- Ensure plugin was installed successfully: `/plugin list --installed`
-- Check if plugin is enabled: `/plugin status plugin-name`
-- Restart Claude Code: `exit` and reopen
+- Ensure plugin was installed successfully: `/plugin list`
+- Check if plugin is enabled: `/plugin list --enabled`
+- Check whether it's active yet — see the install summary guidance in [Installation Methods](#installation-methods): `Plugin is now active.` needs no action, `Run /reload-plugins to activate.` means run that command (a restart is not required)
 - Check for naming conflicts with existing commands
 
 ### Hook Execution Issues
@@ -1222,14 +1226,15 @@ The following Claude Code features work together with plugins:
 
 ---
 
-**Last Updated**: August 15, 2026
-**Claude Code Version**: 2.1.233
+**Last Updated**: August 19, 2026
+**Claude Code Version**: 2.1.235
 **Sources**:
 - https://code.claude.com/docs/en/plugins
 - https://code.claude.com/docs/en/changelog#2-1-172
 - https://code.claude.com/docs/en/changelog
 - https://code.claude.com/docs/en/commands
 - https://code.claude.com/docs/en/plugin-marketplaces
+- https://code.claude.com/docs/en/discover-plugins.md
 - https://github.com/anthropics/claude-code/releases/tag/v2.1.117
 - https://github.com/anthropics/claude-code/releases/tag/v2.1.118
 - https://github.com/anthropics/claude-code/releases/tag/v2.1.131