Feature Request: Support @path imports in SKILL.md

Problem

Currently, @path/to/import syntax only works in CLAUDE.md files, not in SKILL.md files.

This creates a DRY violation when using subagents:

• Rules in .claude/rules/ work in main conversation (auto-loaded based on paths field)
• But subagents don't inherit rules, so we need to duplicate content in skills

Current workaround

Copy the entire content from rules files into SKILL.md, leading to:

• Duplicated content between .claude/rules/*.md and .claude/skills/*/SKILL.md
• Manual sync required when rules change
• Increased maintenance burden

Example scenario

We have coding standards in .claude/rules/go.md:

---
paths:
  - "**/*.go"
---

# Go Coding Standards
- Use `ctx` as context.Context variable name
- Always use named placeholders in SQL
...

For subagents to follow these standards, we must:

1. Create a skill that duplicates the rules content
2. Add the skill to subagent's skills: field
3. Manually keep both files in sync

Proposed solution

Support @path imports in SKILL.md files:

---
name: go-coding
description: Go coding standards
---

@../../rules/go.md

This would allow skills to reference rules without duplication.

Benefits

• DRY: Single source of truth for coding standards
• Consistency: Rules and skills always in sync
• Maintainability: Update once, apply everywhere
• Flexibility: Teams can organize standards in rules and share them with subagents

Use case

Teams maintaining coding standards in .claude/rules/ who also use subagents for specialized tasks (code review, testing, etc.).

Related documentation

• CLAUDE.md imports - Shows @path syntax works in CLAUDE.md
• Skills - No mention of @path imports
• Subagents - Preload skills - Skills are injected at startup