chore: housekeeping and refactoring (bump to 4.7.1)

- Remove unused parameters, dead files, and inaccurate doc.go files
- Extract shared helpers, eliminate duplication
- Rename cheatpath.Cheatpath to cheatpath.Path
- Optimize filesystem walks (WalkDir, skip .git)
- Move sheet name validation to sheet.Validate
- Move integration tests to test/integration/
- Consolidate internal/mock into mocks/
- Move fuzz.sh to test/
- Inline loadSheets helper into command callers
- Extract config.New into its own file
- Fix stale references in HACKING.md and CLAUDE.md
- Restore plan9 build target
- Remove redundant and low-value tests
- Clean up project documentation

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

internal/display/doc.go

@@ -1,45 +0,0 @@
-// Package display handles output formatting and presentation for the cheat application.
-//
-// The display package provides utilities for:
-//   - Writing output to stdout or a pager
-//   - Formatting text with indentation
-//   - Creating faint (dimmed) text for de-emphasis
-//   - Managing colored output
-//
-// # Pager Integration
-//
-// The package integrates with system pagers (less, more, etc.) to handle
-// long output. If a pager is configured and the output is to a terminal,
-// content is automatically piped through the pager.
-//
-// # Text Formatting
-//
-// Various formatting utilities are provided:
-//   - Faint: Creates dimmed text using ANSI escape codes
-//   - Indent: Adds consistent indentation to text blocks
-//   - Write: Intelligent output that uses stdout or pager as appropriate
-//
-// Example Usage
-//
-//	// Write output, using pager if configured
-//	if err := display.Write(output, config); err != nil {
-//	    log.Fatal(err)
-//	}
-//
-//	// Create faint text for de-emphasis
-//	fainted := display.Faint("(read-only)", config)
-//
-//	// Indent a block of text
-//	indented := display.Indent(text, "  ")
-//
-// # Color Support
-//
-// The package respects the colorization settings from the config.
-// When colorization is disabled, formatting functions like Faint
-// return unmodified text.
-//
-// # Terminal Detection
-//
-// The package uses isatty to detect if output is to a terminal,
-// which affects decisions about using a pager and applying colors.
-package display

internal/display/faint.go

@@ -2,17 +2,13 @@
 // cheatsheet content to stdout, or alternatively the system pager.
 package display
 
-import (
-	"fmt"
-
-	"github.com/cheat/cheat/internal/config"
-)
+import "fmt"
 
 // Faint returns a faintly-colored string that's used to de-prioritize text
 // written to stdout
-func Faint(str string, conf config.Config) string {
+func Faint(str string, colorize bool) string {
 	// make `str` faint only if colorization has been requested
-	if conf.Colorize {
+	if colorize {
 		return fmt.Sprintf("\033[2m%s\033[0m", str)
 	}
 

internal/display/faint_test.go

@@ -1,26 +1,20 @@
 package display
 
-import (
-	"testing"
-
-	"github.com/cheat/cheat/internal/config"
-)
+import "testing"
 
 // TestFaint asserts that Faint applies faint formatting
 func TestFaint(t *testing.T) {
 
 	// case: apply colorization
-	conf := config.Config{Colorize: true}
 	want := "\033[2mfoo\033[0m"
-	got := Faint("foo", conf)
+	got := Faint("foo", true)
 	if want != got {
 		t.Errorf("failed to faint: want: %s, got: %s", want, got)
 	}
 
 	// case: do not apply colorization
-	conf.Colorize = false
 	want = "foo"
-	got = Faint("foo", conf)
+	got = Faint("foo", false)
 	if want != got {
 		t.Errorf("failed to faint: want: %s, got: %s", want, got)
 	}

internal/display/write.go

@@ -24,7 +24,7 @@ func Write(out string, conf config.Config) {
 
 // writeToPager writes output through a pager command
 func writeToPager(out string, conf config.Config) {
-	parts := strings.Split(conf.Pager, " ")
+	parts := strings.Fields(conf.Pager)
 	pager := parts[0]
 	args := parts[1:]