branding: make product identity runtime-configurable

Adopt upstream owpengram/owpengram-server's branding.Config/Configure/
Current in place of the old package-level constants. This is the piece the
earlier merge attempt was blocked on (internal/branding failed to import
during that merge). The default identity is unchanged -- every existing
ProductName/ProductUsername/... default still reads "OwpenGram" -- so this
is a pure capability add: nothing currently calls Configure, and every call
site now reads the current snapshot via a function instead of a compile-time
constant.

Five string templates that concatenated branding.ProductName into a `const`
had to become `var`, since a func call is no longer a valid const operand.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/app/account/lifecycle.go

@@ -80,7 +80,7 @@ func (s *Service) DeleteAccount(ctx context.Context, userID int64, authKeyID [8]
 	}
 	executeAt := now.Add(accountDeletionDelay)
 	message := fmt.Sprintf(
-		"A request was made to delete your "+branding.ProductName+" account. If this wasn't you, cancel the request: tg://confirmphone?phone=%s&hash=%s",
+		"A request was made to delete your "+branding.ProductName()+" account. If this wasn't you, cancel the request: tg://confirmphone?phone=%s&hash=%s",
 		url.QueryEscape(snapshot.User.Phone), url.QueryEscape(rawToken),
 	)
 	pending, _, err := s.lifecycle.ScheduleAccountDeletion(ctx, domain.ScheduleAccountDeletion{

internal/app/auth/service.go

@@ -1535,9 +1535,9 @@ func (s *Service) passwordNeeded(ctx context.Context, userID int64) (bool, error
 	return found && settings.HasPassword, nil
 }
 
-const loginMessageTpl = `Login code: %s. Do not give this code to anyone, even if they say they are from ` + branding.ProductName + `!
+var loginMessageTpl = `Login code: %s. Do not give this code to anyone, even if they say they are from ` + branding.ProductName() + `!
 
-This code can be used to log in to your ` + branding.ProductName + ` account. We never ask it for anything else.
+This code can be used to log in to your ` + branding.ProductName() + ` account. We never ask it for anything else.
 
 If you didn't request this code by trying to log in on another device, simply ignore this message.`
 

internal/app/bots/botfather.go

@@ -51,7 +51,7 @@ const (
 	maxTelegramLoginCommandsPerMessage = 32
 )
 
-const botFatherHelpText = `I can help you create and manage ` + branding.ProductName + ` bots.
+var botFatherHelpText = `I can help you create and manage ` + branding.ProductName() + ` bots.
 
 You can control me by sending these commands:
 

internal/app/bots/verifierbot.go

@@ -194,13 +194,13 @@ const (
 
 // verifierBotWhatText is the part of /start that is true whether or not an
 // operator has activated this bot, so it is said first and unconditionally.
-const verifierBotWhatText = `I hand out THIRD-PARTY verification.
+var verifierBotWhatText = `I hand out THIRD-PARTY verification.
 
 A third-party mark is a verifier's own icon, shown right before the name of a bot, a channel or an account, plus one line of description in its profile. It means "this verifier vouches for this peer" -- nothing more.
 
-It is NOT the official ` + branding.ProductName + ` checkmark. The platform badge is granted by the platform itself (@verifybot collects those applications); a third-party mark is granted by the company running a verifier bot. The two are stored, shown and taken away separately, and neither one implies the other.`
+It is NOT the official ` + branding.ProductName() + ` checkmark. The platform badge is granted by the platform itself (@verifybot collects those applications); a third-party mark is granted by the company running a verifier bot. The two are stored, shown and taken away separately, and neither one implies the other.`
 
-const verifierBotHelpText = `I am a verifier bot. I grant third-party marks: my icon before the name of your bot, channel or account, plus a description in its profile. This is not the official ` + branding.ProductName + ` checkmark.
+var verifierBotHelpText = `I am a verifier bot. I grant third-party marks: my icon before the name of your bot, channel or account, plus a description in its profile. This is not the official ` + branding.ProductName() + ` checkmark.
 
 /start - what a third-party mark is and who grants it
 /verify - apply for the mark
@@ -1121,7 +1121,7 @@ func verifierSummaryText(state domain.BotChatState, settings domain.BotVerifierS
 	b.WriteString("\n\nWhy:\n")
 	b.WriteString(state.Draft[verifierDraftReason])
 	b.WriteString("\n\nThis is a third-party mark, not the official ")
-	b.WriteString(branding.ProductName)
+	b.WriteString(branding.ProductName())
 	b.WriteString(" checkmark, and I do not decide: an operator reads the application and either grants the mark or refuses it. I will message you here either way.")
 	return b.String()
 }
@@ -1170,7 +1170,7 @@ func verifierDecisionText(req domain.CustomVerificationRequest) (string, bool) {
 	switch req.Status {
 	case domain.CustomVerificationApproved:
 		return fmt.Sprintf("Application #%d is approved: %s now carries my mark -- my icon before the name and my description in the profile.\n\nThis is a third-party mark, not the official %s checkmark. Send /revoke if you ever want it removed.",
-			req.ID, label, branding.ProductName), true
+			req.ID, label, branding.ProductName()), true
 	case domain.CustomVerificationRejected:
 		text := fmt.Sprintf("Application #%d for %s was not approved, so no mark was granted.", req.ID, label)
 		if reason := strings.TrimSpace(req.DecisionReason); reason != "" {

internal/app/bots/verifybot.go

@@ -114,7 +114,7 @@ const (
 	verifyChoiceBlockedPrefix  = "no:"
 )
 
-const verifyBotStartText = `I collect applications for official ` + branding.ProductName + ` verification: the badge shown next to the name of a channel, supergroup or bot whose identity has been confirmed.
+var verifyBotStartText = `I collect applications for official ` + branding.ProductName() + ` verification: the badge shown next to the name of a channel, supergroup or bot whose identity has been confirmed.
 
 Before you apply, check that the subject of the application:
 - is a channel, supergroup or bot with a public @username;
@@ -126,7 +126,7 @@ This badge is never sold and never granted automatically. A person reads every a
 
 Tap the button below, or send /new, to start. Send /help for the full list of commands.`
 
-const verifyBotHelpText = `I collect official ` + branding.ProductName + ` verification applications.
+var verifyBotHelpText = `I collect official ` + branding.ProductName() + ` verification applications.
 
 /new - file a verification application
 /status - list your applications and their status

internal/app/botverification/seed.go

@@ -42,7 +42,7 @@ func (s *Service) SeedDefaultVerifier(ctx context.Context) (bool, error) {
 	if _, err := s.GrantVerifier(ctx, domain.BotVerifierSettings{
 		BotID:                      domain.VerifierBotUserID,
 		IconDocumentID:             icon.DocumentID,
-		CompanyName:                branding.ProductName,
+		CompanyName:                branding.ProductName(),
 		DefaultDescription:         "Bundled reference verifier -- auto-granted on first boot.",
 		CanModifyCustomDescription: false,
 		Enabled:                    true,

internal/app/langpack/service.go

@@ -54,7 +54,7 @@ func newServiceWithCacheLimits(packs store.LangPackStore, maxBytes int64, maxEnt
 		packs:         packs,
 		packCache:     newLangPackCache(maxBytes, maxEntries),
 		languageCache: newLanguageListCache(languageEntries),
-		publicBaseURL: branding.DefaultPublicURL,
+		publicBaseURL: branding.PublicBaseURL(),
 	}
 }
 

internal/app/passkey/service.go

@@ -71,7 +71,7 @@ func NewService(creds store.PasskeyStore, challenges store.PasskeyChallengeStore
 		creds:        creds,
 		challenges:   challenges,
 		rpID:         rpID,
-		rpName:       branding.ProductName,
+		rpName:       branding.ProductName(),
 		dcID:         dcID,
 		challengeTTL: defaultChallengeTTL,
 		now:          time.Now,