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/ui/app/searchview.go

@@ -203,7 +203,7 @@ func (m *Model) fillSearch(keep bool) {
 				id:    accountScope + p.ID(), kind: k, mark: m.coverageMark(ofProvider(p.ID())),
 			})
 			for _, o := range sources {
-				if providerOf(o.group) == p.ID() {
+				if cachefile.ProviderOf(o.group) == p.ID() {
 					o.label = "  " + o.label
 					scopes = append(scopes, o)
 				}
@@ -267,7 +267,7 @@ func (v *searchView) match() []option {
 	default:
 		account, ofAccount := v.scopeAccount()
 		for _, o := range v.items {
-			if sc.id == allSources || ofAccount && providerOf(o.group) == account || sc.group != "" && o.group == sc.group {
+			if sc.id == allSources || ofAccount && cachefile.ProviderOf(o.group) == account || sc.group != "" && o.group == sc.group {
 				cand = append(cand, o)
 			}
 		}
@@ -523,7 +523,7 @@ func (m *Model) searchLoads() tea.Cmd {
 		return m.startCrawlOf(v.scopeFilter())
 	}
 	if !v.onSource() {
-		return m.startCrawl()
+		return m.startCrawlOf(nil)
 	}
 	providerID, sourceID := splitSourceRow(sc.group)
 	for _, src := range m.sourceResults[providerID].sources {