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/doctor.go

@@ -83,7 +83,7 @@ problem comes with the command that fixes it. tea doctor fails when a check fail
 func (a *application) diagnose(ctx context.Context) doctorReport {
 	var report doctorReport
 	add := func(check doctorCheck) { report.Checks = append(report.Checks, check) }
-	snapshot, err := a.deps.Settings.Load()
+	snapshot, err := a.settings()
 	if err != nil {
 		add(doctorCheck{"Config", checkFailed, err.Error(), "repair or move the file; tea config path prints both files"})
 		add(a.gitCheck(ctx, ""))