Allow to ignore ~/.claude/skills

[hongquan]

Claude skill does not conform agentskill spec. For example, this is one such case:

---
name: hc-plan
description: "Turns a task into a structured, phased plan through research, codebase analysis, and adversarial review. Auto-detects research depth. Use --deep for architecture decisions requiring maximum scrutiny."
when_to_use: "Invoke when planning a new feature or complex task before implementation."
user-invocable: true
argument-hint: "<task> [--quick] [--deep] [--auto] [--tdd] | red-team [plan-path] | validate [plan-path]"
metadata:
  category: workflow
  keywords: [planning, architecture, phases, roadmap, research, design]
---

# Plan — Phased Implementation Roadmaps

Turns a task description into a structured, phased plan through research, codebase analysis, and adversarial review. Never writes implementation code — only plan artifacts.

## Usage

\```
{skill:hc-plan} <task> [--quick] [--deep] [--auto] [--tdd]
{skill:hc-plan} red-team [plan-path]
{skill:hc-plan} validate [plan-path]
\```

If invoked without arguments or with ambiguous intent, use `AskUserQuestion` (header: "Planning Operation") to clarify task scope before proceeding.

When Crush scan and encounter these skills, it got error in parsing and show these skills in the list with errors. It is not relevant to show, because these skill files should be ingored.

[hongquan]

@Amolith Could you take a look?