fix(extract): exclude .worktrees/ from template extraction

Git worktrees are working copies, not part of the project source.
Without this, extract would template duplicate files from any
active worktrees in the project.

Author: raiderrobert

src/extract/exclude.rs

@@ -28,6 +28,7 @@ const DEFAULT_EXCLUDES: &[&str] = &[
     ".nuxt",
     ".output",
     ".turbo",
+    ".worktrees",
     ".diecut-answers.toml",
 ];