refactor: load settings once per run and reuse shared helpers

The application caches the settings snapshot and reloads it only after
an update through the store, so output and prompt helpers no longer
read and parse config.yml and hosts.yml several times per command.
canPrompt and chooser replace the inline prompt-policy checks.

Checks are tallied by one services.Tally, terminal.Plural replaces the
two app copies, refKind.article/noun replace the comment group's own
words, list commands use servicePage, and web URLs are built by
repositoryURL and webURL in browser.go.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/webhooks.go

@@ -365,11 +365,7 @@ $ tea webhook create https://hooks.slack.com/services/T0/B0/X --org acme --type
 		}
 		askAuthorization := !create && authSources == 0
 		if askAuthorization {
-			snapshot, err := a.deps.Settings.Load()
-			if err != nil {
-				return err
-			}
-			if !a.policy(snapshot).CanPrompt(a.deps.Streams) {
+			if !a.canPrompt() {
 				return clierr.Wrap(clierr.Usage, errors.New("editing a webhook drops its stored authorization header unless it is sent again, and Gitea never returns it: pass --authorization-header-file or --authorization-header (use --clear-authorization only for a hook without one)"))
 			}
 		}