feat: Improve export self-containment and link handling

- Use absolute paths for path_relative calculations
- Validate links before export to populate page.links
- Copy cross-collection referenced pages for self-contained export
- Update export_link_path to generate local links for self-contained exports
- Remove page from visited map to allow re-inclusion in other contexts

lib/data/atlas/collection.v

@@ -53,7 +53,10 @@ fn (mut c Collection) add_page(mut path pathlib.Path) ! {
 	if name in c.pages {
 		return error('Page ${name} already exists in collection ${c.name}')
 	}
-	relativepath := path.path_relative(c.path()!.path)!
+	// Use absolute paths for path_relative to work correctly
+	mut col_path := pathlib.get(c.path)
+	mut page_abs_path := pathlib.get(path.absolute())
+	relativepath := page_abs_path.path_relative(col_path.absolute())!
 
 	mut p_new := Page{
 		name:            name
@@ -71,7 +74,10 @@ fn (mut c Collection) add_file(mut p pathlib.Path) ! {
 	if name in c.files {
 		return error('Page ${name} already exists in collection ${c.name}')
 	}
-	relativepath := p.path_relative(c.path()!.path)!
+	// Use absolute paths for path_relative to work correctly
+	mut col_path := pathlib.get(c.path)
+	mut file_abs_path := pathlib.get(p.absolute())
+	relativepath := file_abs_path.path_relative(col_path.absolute())!
 
 	mut file_new := File{
 		name:       name

lib/data/atlas/export.v

@@ -22,8 +22,8 @@ pub fn (mut a Atlas) export(args ExportArgs) ! {
 		dest.empty()!
 	}
 
-	// Validate links before export
-	// a.validate_links()!
+	// Validate links before export to populate page.links
+	a.validate_links()!
 
 	for _, mut col in a.collections {
 		col.export(
@@ -67,6 +67,10 @@ pub fn (mut c Collection) export(args CollectionExportArgs) ! {
 	)!
 	json_file.write(meta)!
 
+	// Track cross-collection pages that need to be copied for self-contained export
+	mut cross_collection_pages := map[string]&Page{} // key: page.name, value: &Page
+
+	// First pass: export all pages in this collection and collect cross-collection references
 	for _, mut page in c.pages {
 		// Get content with includes processed and links transformed for export
 		content := page.content_with_fixed_links(
@@ -78,6 +82,19 @@ pub fn (mut c Collection) export(args CollectionExportArgs) ! {
 		mut dest_file := pathlib.get_file(path: '${col_dir.path}/${page.name}.md', create: true)!
 		dest_file.write(content)!
 
+		// Collect cross-collection page references for copying
+		// IMPORTANT: Use cached links from validation (before transformation) to preserve collection info
+		for mut link in page.links {
+			// Only process valid page links (not files/images) from other collections
+			if link.status == .found && !link.is_file_link && !link.is_local_in_collection() {
+				mut target_page := link.target_page() or { continue }
+				// Use page name as key to avoid duplicates
+				if target_page.name !in cross_collection_pages {
+					cross_collection_pages[target_page.name] = target_page
+				}
+			}
+		}
+
 		// Redis operations...
 		if args.redis {
 			mut context := base.context()!
@@ -86,23 +103,17 @@ pub fn (mut c Collection) export(args CollectionExportArgs) ! {
 		}
 	}
 
-	// // Export files
-	// if c.files.len > 0 {
-	// 	files_dir := pathlib.get_dir(
-	// 		path:   '${col_dir.path}/files'
-	// 		create: true
-	// 	)!
+	// Second pass: copy cross-collection referenced pages to make collection self-contained
+	for _, mut ref_page in cross_collection_pages {
+		// Get the referenced page content with includes processed
+		ref_content := ref_page.content_with_fixed_links(
+			include:          args.include
+			cross_collection: true
+			export_mode:      true
+		)!
 
-	// 	for _, mut file in c.files {
-	// 		dest_path := '${files_dir.path}/${file.file_name()}'
-	// 		mut p2 := file.path()!
-	// 		p2.copy(dest: col_dir.path)!
-
-	// 		if args.redis {
-	// 			mut context := base.context()!
-	// 			mut redis := context.redis()!
-	// 			redis.hset('atlas:${c.name}', file.file_name(), file.path()!.path)!
-	// 		}
-	// 	}
-	// }
+		// Write the referenced page to this collection's directory
+		mut dest_file := pathlib.get_file(path: '${col_dir.path}/${ref_page.name}.md', create: true)!
+		dest_file.write(ref_content)!
+	}
 }

lib/data/atlas/link.v

@@ -242,27 +242,20 @@ fn (mut p Page) calculate_link_path(mut link Link, args FixLinksArgs) !string {
 	return p.filesystem_link_path(mut link)!
 }
 
-// export_link_path calculates path for export (flat structure: collection/file.md)
+// export_link_path calculates path for export (self-contained: all references are local)
 fn (mut p Page) export_link_path(mut link Link) !string {
-	mut target_collection := ''
 	mut target_filename := ''
 
 	if link.is_file_link {
 		mut tf := link.target_file()!
-		target_collection = tf.collection.name
 		target_filename = tf.name
 	} else {
 		mut tp := link.target_page()!
-		target_collection = tp.collection.name
 		target_filename = '${tp.name}.md'
 	}
 
-	// Same collection: just filename, different collection: ../collection/filename
-	return if link.is_local_in_collection() {
-		target_filename
-	} else {
-		'../${target_collection}/${target_filename}'
-	}
+	// For self-contained exports, all links are local (cross-collection pages are copied)
+	return target_filename
 }
 
 // filesystem_link_path calculates path using actual filesystem paths

lib/data/atlas/page.v

@@ -128,6 +128,10 @@ fn (mut p Page) process_includes(content string, mut visited map[string]bool) !s
 		}
 	}
 
+	// Remove this page from visited map to allow it to be included again in other contexts
+	// This prevents false positives when a page is included multiple times (which is valid)
+	visited.delete(page_key)
+
 	return processed_lines.join_lines()
 }