perf(copy): limit find depth for simple directory patterns

When copying directories with simple basename patterns (e.g., `.serena`,
`node_modules`), `find` was scanning the entire repository tree recursively.
In repos with large directories like `node_modules` (2GB+), this caused
~11 seconds of unnecessary I/O per pattern.

Add `-maxdepth 1` for non-slash patterns since `gtr.copy.includeDirs`
entries are typically top-level directories. Patterns with slashes
(e.g., `vendor/bundle`) retain recursive behavior via `-path`.

Before: ~11s per pattern (full recursive find)
After:  ~0.03s per pattern (top-level only)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: akirasosa

lib/copy.sh

@@ -331,10 +331,11 @@ copy_directories() {
     # Find directories matching the pattern
     # Use -path for patterns with slashes (e.g., vendor/bundle), -name for basenames
     # Note: case inside $() inside heredocs breaks Bash 3.2, so compute first
+    # Use -maxdepth 1 for simple basenames to avoid scanning entire repo (e.g., node_modules)
     local find_results
     case "$pattern" in
       */*) find_results=$(find . -type d -path "./$pattern" 2>/dev/null) ;;
-      *)   find_results=$(find . -type d -name "$pattern" 2>/dev/null) ;;
+      *)   find_results=$(find . -maxdepth 1 -type d -name "$pattern" 2>/dev/null) ;;
     esac
 
     while IFS= read -r dir_path; do