refactor: drop dead code and use the standard library where it already does the job (#76)

No behaviour change.

- Deleted, unused or one-line wrappers: panes.RuneIndexes, Detail.Refresh (SetDescribed does it), SecretValue.Len, Query.Empty, Clipboard.Native, config.Load, get's value, Model.done, providerOf (cachefile.ProviderOf), contextWithTimeout, searchCoverage, startCrawl, showKeybindings, the expiry aliases and daysLeft.
- cmp.Or instead of the two cmpOr copies; slices.Sorted(maps.Keys(…)), maps.Copy, wg.Go, utf8.RuneCountInString and new(true) instead of loops and helpers that do the same.
- A container's pane title is set once, not twice; a redundant length check in share links and a no-op assignment in linkhandler.Launch are gone.
- Tests call ansi.Strip and lastLines directly; gofmt -s on links.go.

Reviewed-on: #76
Co-authored-by: Karl-Einar Bergstrøm <karl-einarb@outlook.com>

internal/provider/azure/details.go

@@ -2,6 +2,7 @@ package azure
 
 import (
 	"fmt"
+	"maps"
 	"slices"
 	"strings"
 
@@ -134,12 +135,7 @@ func (v vaultInfo) attrs() []provider.Attr {
 	if v.endpoints > 0 {
 		add("private", fmt.Sprintf("%d endpoint%s", v.endpoints, map[bool]string{true: "s"}[v.endpoints > 1]))
 	}
-	keys := make([]string, 0, len(v.tags))
-	for k := range v.tags {
-		keys = append(keys, k)
-	}
-	slices.Sort(keys)
-	for i, k := range keys {
+	for i, k := range slices.Sorted(maps.Keys(v.tags)) {
 		label := ""
 		if i == 0 {
 			label = "tags"