v0.88.0: app-email SMTP relay (in-process shim + per-app injection)

In-process go-smtp shim (Shape 1): apps → shim → hub → Resend, Resend key stays
hub-side. From-header allowlist (reject 5xx pre-hub), single-shot raw-MIME forward,
status→SMTP mapping. Global + per-app toggles gate compose-time env injection from
.felhom.yml smtp_mapping. Hungarian UI on settings + app config pages.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

controller/internal/settings/settings.go

@@ -64,6 +64,17 @@ type Settings struct {
 
 	// App-to-app integration state (e.g., "onlyoffice:filebrowser" → state)
 	Integrations map[string]IntegrationState `json:"integrations,omitempty"`
+
+	// AppEmail is the global app-email (SMTP relay) toggle. When on, deployed apps with an
+	// smtp_mapping can send mail via the in-controller shim → hub → Resend. Relay-only:
+	// no BYO host/port/user/pass (that escape hatch is deferred).
+	AppEmail *AppEmail `json:"app_email,omitempty"`
+}
+
+// AppEmail holds the global app-email toggle and an optional household display name.
+type AppEmail struct {
+	Enabled  bool   `json:"enabled"`
+	FromName string `json:"from_name,omitempty"` // optional household display name for the From line
 }
 
 // IntegrationState holds the state of a provider:target integration pair.
@@ -1178,6 +1189,36 @@ func (s *Settings) SetGeoSyncState(zoneID, rulesetID, syncError string) error {
 	return s.save()
 }
 
+// --- App email (SMTP relay) ---
+
+// GetAppEmail returns the global app-email toggle (a copy; never the live pointer).
+func (s *Settings) GetAppEmail() AppEmail {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	if s.AppEmail == nil {
+		return AppEmail{}
+	}
+	return *s.AppEmail
+}
+
+// AppEmailEnabled reports whether app-email is globally on.
+func (s *Settings) AppEmailEnabled() bool {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.AppEmail != nil && s.AppEmail.Enabled
+}
+
+// SetAppEmail updates the global app-email toggle and persists it.
+func (s *Settings) SetAppEmail(enabled bool, fromName string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.debug {
+		s.log.Printf("[DEBUG] [settings] SetAppEmail enabled=%v from_name=%q", enabled, fromName)
+	}
+	s.AppEmail = &AppEmail{Enabled: enabled, FromName: strings.TrimSpace(fromName)}
+	return s.save()
+}
+
 // --- App-to-app integrations ---
 
 // GetIntegrationState returns the state for a specific integration key (e.g., "onlyoffice:filebrowser").