docs: sync to Claude Code v2.1.131 (3 patches since v2.1.126)

Sync covers v2.1.128, v2.1.129, and v2.1.131 (May 2026). Highlights:
gateway /v1/models discovery is now opt-in (CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY),
added --plugin-url flag, disableRemoteControl setting, /mcp tool-count display,
expanded skillOverrides values, /context viz no longer leaks into conversation,
Ctrl+R cross-project default. Also reconciles slash-command count to 60+ and
fixes the skill-count entry in CATALOG.

03-skills/README.md

@@ -649,6 +649,27 @@ Skill(deploy *)
 
 **Hide individual skills** by adding `disable-model-invocation: true` to their frontmatter.
 
+### Controlling Skill Override Behavior (`skillOverrides`)
+
+When a project skill and a user skill share the same name, project wins by default. The `skillOverrides` setting (v2.1.129+) lets you tune this. Add it to `~/.claude/settings.json` or project `.claude/settings.json`:
+
+```json
+{
+  "skillOverrides": "name-only"
+}
+```
+
+Accepted values:
+
+| Value | Behavior |
+|-------|----------|
+| `"on"` (default) | A repo skill can override a user skill of the same name. |
+| `"off"` | Disable overriding entirely — user skills always win. |
+| `"name-only"` | Match overrides only on skill name (ignore description / source). |
+| `"user-invocable-only"` | Only user-invocable skills can be overridden — model-invoked skills always come from their original location. |
+
+Useful when team policy says "user-defined skills must always take precedence" (`"off"`) or "only allow narrow name-based overrides" (`"name-only"`).
+
 ## Best Practices
 
 ### 1. Make Descriptions Specific
@@ -823,8 +844,8 @@ Once you start building skills seriously, two things become essential: a library
 - [Hooks Guide](../06-hooks/) - Event-driven automation
 
 ---
-**Last Updated**: May 2, 2026
-**Claude Code Version**: 2.1.126
+**Last Updated**: May 6, 2026
+**Claude Code Version**: 2.1.131
 **Sources**:
 - https://code.claude.com/docs/en/skills
 - https://code.claude.com/docs/en/settings