+code-quality Add slice capacity pre-allocation in loadAllPosts and paginate

- loadAllPosts: pre-allocate posts slice with capacity len(entries) since
  each directory entry may become a post.
- paginate: pre-allocate pages slice with capacity (len(posts)+pageSize-1)/pageSize.

The concat function no longer exists in the codebase (removed when theme
sound data was moved to embedded JSON files in commit 06dd860).

1 files changed, 3 insertions, 2 deletions

diff --git a/internal/generator/generator.go b/internal/generator/generator.go
index 1bdd7c7..533a771 100644
--- a/internal/generator/generator.go
+++ b/internal/generator/generator.go
@@ -124,7 +124,7 @@ func loadAllPosts(outputDir string) ([]*post.Post, error) {
 		return nil, fmt.Errorf("read posts dir: %w", err)
 	}
 
-	var posts []*post.Post
+	posts := make([]*post.Post, 0, len(entries))
 
 	for _, entry := range entries {
 		if !entry.IsDir() {
@@ -144,7 +144,8 @@ func loadAllPosts(outputDir string) ([]*post.Post, error) {
 
 // paginate splits posts into chunks of size pageSize.
 func paginate(posts []*post.Post, pageSize int) [][]*post.Post {
-	var pages [][]*post.Post
+	pageCount := (len(posts) + pageSize - 1) / pageSize
+	pages := make([][]*post.Post, 0, pageCount)
 
 	for i := 0; i < len(posts); i += pageSize {
 		end := i + pageSize