fix(tls): o painel de seguranca estava vazio em qualquer modo menos um

/admin/security mostrava "Nao foi possivel carregar os dados" porque
/api/v1/admin/tls respondia 503. A rota so era ligada quando o certificado
vinha do watcher do acme.json do Traefik, o unico provider que tinha metodos
de estado proprios.

Nesta instalacao o TRAEFIK_ACME_DIR nao esta definido e o STATIC_CERT_PATH
tambem nao, portanto o servidor cai no certificado autoassinado efemero -- ou
seja, o painel calava-se exactamente no estado em que o operador mais precisa
de ser avisado.

- ProviderStatus deriva o estado de qualquer port.CertProvider, lendo a folha
  do certificado que ele realmente serve
- o painel passa a ser ligado sempre que ha JWT_SECRET
- passa a dizer quem emitiu e se e autoassinado, com um aviso proprio: nas
  portas de correio um autoassinado e recusado por qualquer cliente que
  verifique, o que pesa mais do que uma validade ainda longe

CheckSignatureFrom nao serve para detectar isto: tambem exige que o emissor
seja uma CA, coisa que uma folha descartavel nunca declara, e por isso dava a
fallback degradada como correctamente emitida.

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

services/protocols/internal/infrastructure/tls/provider_status.go

@@ -0,0 +1,96 @@
+package tlsprovider
+
+import (
+	"bytes"
+	"crypto/tls"
+	"crypto/x509"
+	"time"
+
+	"lambdamail/protocols/internal/application/port"
+)
+
+// ProviderStatus reports on whatever certificate a provider is actually
+// serving, by asking it for one and reading the leaf.
+//
+// The TLS panel used to be wired only when the certificate came from the
+// Traefik acme.json watcher, the single provider that carried status methods
+// of its own. Every other mode answered 503 "the TLS panel needs a certificate
+// watcher" - including the degraded fallback, where the server serves an
+// ephemeral self-signed certificate and the operator most needs to be told.
+type ProviderStatus struct {
+	provider port.CertProvider
+}
+
+func NewProviderStatus(provider port.CertProvider) *ProviderStatus {
+	return &ProviderStatus{provider: provider}
+}
+
+// leafFor returns the parsed leaf the provider would serve for a host.
+func (s *ProviderStatus) leafFor(host string) *x509.Certificate {
+	if s == nil || s.provider == nil {
+		return nil
+	}
+	cert, err := s.provider.GetCertificate(&tls.ClientHelloInfo{ServerName: host})
+	if err != nil || cert == nil {
+		return nil
+	}
+	if cert.Leaf != nil {
+		return cert.Leaf
+	}
+	if len(cert.Certificate) == 0 {
+		return nil
+	}
+	leaf, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		return nil
+	}
+	return leaf
+}
+
+func (s *ProviderStatus) HasCertificateFor(host string) bool {
+	return s.leafFor(host) != nil
+}
+
+// EarliestExpiry reports the expiry of the certificate served for the host it
+// was asked about. A single-certificate provider has only one to report.
+func (s *ProviderStatus) EarliestExpiry() (string, time.Time, bool) {
+	leaf := s.leafFor("")
+	if leaf == nil {
+		return "", time.Time{}, false
+	}
+	host := leaf.Subject.CommonName
+	if host == "" && len(leaf.DNSNames) > 0 {
+		host = leaf.DNSNames[0]
+	}
+	return host, leaf.NotAfter, true
+}
+
+// LastReload and LastChange are unknown for a provider that loads once. The
+// panel already treats a zero time as "not reported" rather than as an error.
+func (s *ProviderStatus) LastReload() time.Time { return time.Time{} }
+func (s *ProviderStatus) LastChange() time.Time { return time.Time{} }
+
+// UnknownSNICount is a watcher-only measure; nothing here counts SNI misses.
+func (s *ProviderStatus) UnknownSNICount() int64 { return 0 }
+
+// CertificateSummary names the issuer and says whether the certificate is
+// self-signed, which is the difference between a working mail server and one
+// every verifying client refuses.
+func (s *ProviderStatus) CertificateSummary(host string) (string, bool, bool) {
+	leaf := s.leafFor(host)
+	if leaf == nil {
+		return "", false, false
+	}
+	issuer := leaf.Issuer.CommonName
+	if issuer == "" {
+		issuer = leaf.Issuer.String()
+	}
+	// Equal subject and issuer is what self-signed means on the wire, and
+	// verifying the signature with the certificate's own key confirms it.
+	// CheckSignatureFrom is the wrong tool: it also demands the issuer be a
+	// CA, which a throwaway leaf never claims to be, so it reported the
+	// degraded fallback as properly issued.
+	selfSigned := bytes.Equal(leaf.RawSubject, leaf.RawIssuer) &&
+		leaf.CheckSignature(leaf.SignatureAlgorithm, leaf.RawTBSCertificate, leaf.Signature) == nil
+	return issuer, selfSigned, true
+}

services/protocols/internal/infrastructure/tls/provider_status_test.go

@@ -0,0 +1,49 @@
+package tlsprovider
+
+import (
+	"testing"
+	"time"
+)
+
+// The TLS panel answered 503 "the TLS panel needs a certificate watcher" on a
+// real deployment, because the panel was only wired when the certificate came
+// from the Traefik acme.json watcher. With TRAEFIK_ACME_DIR unset the server
+// falls back to an ephemeral self-signed certificate - which is exactly the
+// state an operator most needs the panel to show, and precisely the one it
+// refused to report.
+func TestProviderStatus_ReportsAnEphemeralSelfSignedCertificate(t *testing.T) {
+	provider, err := NewEphemeralSelfSignedCertProvider()
+	if err != nil {
+		t.Fatalf("build provider: %v", err)
+	}
+	status := NewProviderStatus(provider)
+
+	if !status.HasCertificateFor("mail.example.test") {
+		t.Error("reported no certificate at all; the server is serving one")
+	}
+
+	host, expiry, ok := status.EarliestExpiry()
+	if !ok {
+		t.Fatal("could not read the expiry, so the panel would show nothing")
+	}
+	if expiry.Before(time.Now()) {
+		t.Errorf("expiry %v is in the past", expiry)
+	}
+	if host == "" {
+		t.Error("no host named for the expiring certificate")
+	}
+
+	// The whole point: an operator must be able to see this is not a real
+	// certificate. Serving self-signed on port 25 and 993 means every client
+	// that verifies is refusing the connection.
+	issuer, selfSigned, ok := status.CertificateSummary("mail.example.test")
+	if !ok {
+		t.Fatal("no summary available")
+	}
+	if !selfSigned {
+		t.Error("an ephemeral self-signed certificate was not reported as self-signed")
+	}
+	if issuer == "" {
+		t.Error("no issuer reported")
+	}
+}