fix(Skills): Skip "DO NOT EDIT" headers for skill files (#70)

* fix(Skills): Skip "DO NOT EDIT" headers for skill files - they are user-editable scaffolding

Skills files are scaffolding code meant to be modified by users to implement
business logic. They should not have "DO NOT EDIT" headers that mislead users
into thinking they cannot modify these files.

The fix:
- Detects skill files by template key (skill.go, skill.rs, skill.ts) or path pattern (/skills/)
- Excludes them from automatic header generation
- Preserves the existing .adl-ignore functionality (skill files are still added automatically)

This resolves the issue where users were confused by skill files having "DO NOT EDIT"
headers despite being intended for user modification.

Fixes #69

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

Co-authored-by: Eden Reich <edenreich@users.noreply.github.com>

* chore: Remove redundant comment

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: Eden Reich <edenreich@users.noreply.github.com>

Author: edenreich

internal/generator/generator.go

@@ -298,7 +298,10 @@ func (g *Generator) generateProject(templateEngine *templates.Engine, adl *schem
 			fileType = "taskfile"
 		}
 
-		if fileType != "" {
+		isSkillFile := (templateKey == "skill.go" || templateKey == "skill.rs" || templateKey == "skill.ts") || 
+			(strings.Contains(fileName, "/skills/") && (ext == ".go" || ext == ".rs" || ext == ".ts"))
+
+		if fileType != "" && !isSkillFile {
 			header := templates.GetGeneratedFileHeader(fileType, ctx.Metadata.CLIVersion, ctx.Metadata.GeneratedAt)
 			content = header + content
 		}