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/config/pager_test.go

@@ -0,0 +1,90 @@
+package config
+
+import (
+	"os"
+	"runtime"
+	"testing"
+)
+
+// TestPager tests the Pager function
+func TestPager(t *testing.T) {
+	// Save original env var
+	oldPager := os.Getenv("PAGER")
+	defer os.Setenv("PAGER", oldPager)
+
+	t.Run("windows default", func(t *testing.T) {
+		if runtime.GOOS != "windows" {
+			t.Skip("skipping windows test on non-windows platform")
+		}
+
+		os.Setenv("PAGER", "")
+		pager := Pager()
+		if pager != "more" {
+			t.Errorf("expected 'more' on windows, got %s", pager)
+		}
+	})
+
+	t.Run("PAGER env var", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping non-windows test on windows platform")
+		}
+
+		os.Setenv("PAGER", "bat")
+		pager := Pager()
+		if pager != "bat" {
+			t.Errorf("expected PAGER env var value, got %s", pager)
+		}
+	})
+
+	t.Run("fallback to system pager", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping non-windows test on windows platform")
+		}
+
+		os.Setenv("PAGER", "")
+		pager := Pager()
+
+		// Should find one of the fallback pagers or return empty string
+		validPagers := map[string]bool{
+			"":      true, // no pager found
+			"pager": true,
+			"less":  true,
+			"more":  true,
+		}
+
+		// Check if it's a path to one of these
+		found := false
+		for p := range validPagers {
+			if p == "" && pager == "" {
+				found = true
+				break
+			}
+			if p != "" && (pager == p || len(pager) >= len(p) && pager[len(pager)-len(p):] == p) {
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			t.Errorf("unexpected pager value: %s", pager)
+		}
+	})
+
+	t.Run("no pager available", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping non-windows test on windows platform")
+		}
+
+		os.Setenv("PAGER", "")
+
+		// Save and modify PATH to ensure no pagers are found
+		oldPath := os.Getenv("PATH")
+		defer os.Setenv("PATH", oldPath)
+		os.Setenv("PATH", "/nonexistent")
+
+		pager := Pager()
+		if pager != "" {
+			t.Errorf("expected empty string when no pager found, got %s", pager)
+		}
+	})
+}