feat: auto-resolve @path references in skill templates to absolute paths

Skill loaders previously only told agents that @path references are
relative to the skill directory, but agents often failed to resolve
them. Now @path/with/slash patterns are automatically expanded to
absolute paths during template construction.

src/shared/skill-path-resolver.ts

@@ -0,0 +1,17 @@
+import { join } from "path"
+
+/**
+ * Resolves @path references in skill content to absolute paths.
+ *
+ * Matches @references that contain at least one slash (e.g., @scripts/search.py, @data/)
+ * to avoid false positives with decorators (@param), JSDoc tags (@ts-ignore), etc.
+ *
+ * Email addresses are excluded since they have alphanumeric characters before @.
+ */
+export function resolveSkillPathReferences(content: string, basePath: string): string {
+	const normalizedBase = basePath.endsWith("/") ? basePath.slice(0, -1) : basePath
+	return content.replace(
+		/(?<![a-zA-Z0-9])@([a-zA-Z0-9_-]+\/[a-zA-Z0-9_.\-\/]*)/g,
+		(_, relativePath: string) => join(normalizedBase, relativePath)
+	)
+}