fix: Use lowercase-with-hyphens skill names for Claude.ai compatibility

Fix skill names in SKILL.md frontmatter to comply with Claude.ai requirements:
"Skill name in SKILL.md can only contain lowercase letters, numbers, and hyphens."

## Changes

Updated skill names from "Title Case With Spaces" to "lowercase-with-hyphens":

1. "n8n Expression Syntax" → "n8n-expression-syntax"
2. "n8n MCP Tools Expert" → "n8n-mcp-tools-expert"
3. "n8n Workflow Patterns" → "n8n-workflow-patterns"
4. "n8n Validation Expert" → "n8n-validation-expert"
5. "n8n Node Configuration" → "n8n-node-configuration"

## Files Modified

- skills/n8n-expression-syntax/SKILL.md
- skills/n8n-mcp-tools-expert/SKILL.md
- skills/n8n-workflow-patterns/SKILL.md
- skills/n8n-validation-expert/SKILL.md
- skills/n8n-node-configuration/SKILL.md

## Distribution Packages

Regenerated all distribution zip files with corrected SKILL.md:
- dist/n8n-expression-syntax-v1.0.0.zip
- dist/n8n-mcp-tools-expert-v1.0.0.zip
- dist/n8n-workflow-patterns-v1.0.0.zip
- dist/n8n-validation-expert-v1.0.0.zip
- dist/n8n-node-configuration-v1.0.0.zip
- dist/n8n-mcp-skills-claude-code-v1.0.0.zip

Skills can now be uploaded to Claude.ai without naming errors.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

skills/n8n-mcp-tools-expert/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: n8n MCP Tools Expert
+name: n8n-mcp-tools-expert
 description: Expert guide for using n8n-mcp MCP tools effectively. Use when searching for nodes, validating configurations, accessing templates, managing workflows, or using any n8n-mcp tool. Provides tool selection guidance, parameter formats, and common patterns.
 ---