chore: bump version to 4.5.0

Bug fixes:
- Fix inverted pager detection logic (returned error instead of path)
- Fix repo.Clone ignoring destination directory parameter
- Fix sheet loading using append on pre-sized slices
- Clean up partial files on copy failure
- Trim whitespace from editor config

Security:
- Add path traversal protection for cheatsheet names

Performance:
- Move regex compilation outside search loop
- Replace string concatenation with strings.Join in search

Build:
- Remove go:generate; embed config and usage as string literals
- Parallelize release builds
- Add fuzz testing infrastructure

Testing:
- Improve test coverage from 38.9% to 50.2%
- Add fuzz tests for search, filter, tags, and validation

Documentation:
- Fix inaccurate code examples in HACKING.md
- Add missing --conf and --all options to man page
- Add ADRs for path traversal, env parsing, and search parallelization
- Update CONTRIBUTING.md to reflect project policy

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

internal/sheet/search.go

@@ -9,16 +9,17 @@ import (
 func (s *Sheet) Search(reg *regexp.Regexp) string {
 
 	// record matches
-	matches := ""
+	var matches []string
 
 	// search through the cheatsheet's text line by line
 	for _, line := range strings.Split(s.Text, "\n\n") {
 
-		// exit early if the line doesn't match the regex
+		// save matching lines
 		if reg.MatchString(line) {
-			matches += line + "\n\n"
+			matches = append(matches, line)
 		}
 	}
 
-	return strings.TrimSpace(matches)
+	// Join matches with the same delimiter used for splitting
+	return strings.Join(matches, "\n\n")
 }