v2.0.47: HTTPS Everywhere — TLS-only control plane, agents/CLI/MCP

Breaking change release. Plaintext HTTP listener removed. The certctl
control plane now terminates TLS 1.3 on :8443 via
http.Server.ListenAndServeTLS. No CERTCTL_TLS_ENABLED=false escape
hatch. No dual-listener mode. One-step cutover per docs/upgrade-to-tls.md.

Server
- cmd/server/tls.go: certHolder with SIGHUP hot-reload + atomic cert
  swap, buildServerTLSConfig (TLS 1.3 min, GetCertificate callback),
  preflightServerTLS validation
- cmd/server/main.go: ListenAndServeTLS in place of ListenAndServe,
  watchSIGHUP wiring, cert/key path config threading
- tls_test.go: 418-line regression coverage of reload, preflight,
  callback behavior, SAN validation

Config
- CERTCTL_TLS_CERT_PATH / CERTCTL_TLS_KEY_PATH (required)
- Plaintext rejection: agents/CLI/MCP pre-flight-fail on http://
  URLs with a pointer to docs/upgrade-to-tls.md

Agents, CLI, MCP
- All three pre-flight-reject http:// URLs with fail-loud diagnostic
- CERTCTL_SERVER_CA_BUNDLE_PATH for private-CA trust
- CERTCTL_SERVER_TLS_INSECURE_SKIP_VERIFY for dev-only bypass
  (loud warning on startup)
- install-agent.sh emits both vars as commented template lines

docker-compose
- certctl-tls-init sidecar generates SAN-valid self-signed cert into
  deploy/test/certs/ on first boot
- All demo-stack curls pin against ca.crt with --cacert

Helm chart
- Three TLS provisioning modes, exactly one required:
  - server.tls.existingSecret (operator-supplied)
  - server.tls.certManager.enabled (cert-manager integration)
  - server.tls.selfSigned.enabled (eval only — not for production)
- server-certificate.yaml template for cert-manager mode
- helm install without a TLS source fails at template render with
  a pointer to docs/tls.md

CI
- .github/workflows/ci.yml Helm Chart Validation step renders the
  chart in both existingSecret and cert-manager modes, plus an
  inverse guard-regression test that asserts helm template MUST
  refuse to render when no TLS source is configured. Previously
  the single `helm template` invocation hit the certctl.tls.required
  fail-loud guard and exit-1'd CI. Four invocations now: lint
  (existingSecret), template (existingSecret), template
  (cert-manager), template (no args — must fail).

Integration tests
- deploy/test/integration_test.go stands up the Compose stack over
  HTTPS, extracts the CA bundle, and exercises every certctl API
  over https://localhost:8443
- All 34 integration subtests green (per Phase 8 local CI-parity)

Documentation
- New: docs/tls.md (provisioning patterns, rotation, SIGHUP reload)
- New: docs/upgrade-to-tls.md (one-step cutover, no-downgrade
  warnings, fleet-roll sequencing)
- CHANGELOG.md: v2.2.0 "HTTPS Everywhere — The Irony" entry
  (file heading unchanged; release tag is v2.0.47)
- All curls in docs/, examples/, deploy/helm/ guides use
  https://localhost:8443 --cacert

Verification
- grep -rn "ListenAndServe[^T]" cmd/ internal/ → 0 hits
- grep -rn "\"http://" cmd/ internal/ → 2 benign hits (Caddy admin
  API default, SSRF doc comment) — zero certctl endpoints
- Tasks #197–#206 (Phases 0–8) all closed in the tracker

Files: 65 changed, 3489 insertions, 372 deletions (pre-CI-fix).

cmd/server/main.go

@@ -736,22 +736,54 @@ func main() {
 		logger.Info("dashboard directory not found, serving API only")
 	}
 
+	// HTTPS-everywhere milestone §2.1: fail-loud if the TLS configuration is
+	// missing or malformed. Duplicates config.Validate() for defense in depth
+	// (same pattern as preflightSCEPChallengePassword).
+	if err := preflightServerTLS(cfg.Server.TLS.CertPath, cfg.Server.TLS.KeyPath); err != nil {
+		logger.Error("startup refused: HTTPS cert unusable; control plane is HTTPS-only",
+			"error", err,
+			"cert_path", cfg.Server.TLS.CertPath,
+			"key_path", cfg.Server.TLS.KeyPath)
+		os.Exit(1)
+	}
+
+	// Load the cert+key into a SIGHUP-reloadable holder. Any subsequent
+	// SIGHUP triggers a fresh read and atomic swap so rotations do not need
+	// a restart. Reload failures keep the previous cert and log a warning.
+	tlsCertHolder, err := newCertHolder(cfg.Server.TLS.CertPath, cfg.Server.TLS.KeyPath)
+	if err != nil {
+		logger.Error("startup refused: failed to load TLS cert holder",
+			"error", err,
+			"cert_path", cfg.Server.TLS.CertPath,
+			"key_path", cfg.Server.TLS.KeyPath)
+		os.Exit(1)
+	}
+	stopTLSWatcher := tlsCertHolder.watchSIGHUP(logger)
+	defer stopTLSWatcher()
+
 	// Server configuration
 	addr := net.JoinHostPort(cfg.Server.Host, strconv.Itoa(cfg.Server.Port))
 	httpServer := &http.Server{
 		Addr:              addr,
 		Handler:           finalHandler,
+		TLSConfig:         buildServerTLSConfig(tlsCertHolder),
 		ReadTimeout:       30 * time.Second,
 		ReadHeaderTimeout: 5 * time.Second,
 		WriteTimeout:      120 * time.Second, // Must accommodate ACME issuance (order + challenge + finalize)
 		IdleTimeout:       60 * time.Second,
 	}
 
-	// Start HTTP server in background
-	logger.Info("starting HTTP server", "address", addr)
+	// Start HTTPS server in background. ListenAndServeTLS is called with
+	// empty cert+key arguments because the cert is sourced through
+	// TLSConfig.GetCertificate (the SIGHUP-reloadable holder). Passing file
+	// paths here would pin the first-loaded cert and defeat hot reload.
+	logger.Info("HTTPS server listening",
+		"address", addr,
+		"cert_path", cfg.Server.TLS.CertPath,
+		"min_version", "TLS1.3")
 	go func() {
-		if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-			logger.Error("HTTP server error", "error", err)
+		if err := httpServer.ListenAndServeTLS("", ""); err != nil && err != http.ErrServerClosed {
+			logger.Error("HTTPS server error", "error", err)
 		}
 	}()
 
@@ -774,9 +806,9 @@ func main() {
 		logger.Warn("scheduler work did not complete in time", "error", err)
 	}
 
-	logger.Info("shutting down HTTP server")
+	logger.Info("shutting down HTTPS server")
 	if err := httpServer.Shutdown(shutdownCtx); err != nil {
-		logger.Error("HTTP server shutdown error", "error", err)
+		logger.Error("HTTPS server shutdown error", "error", err)
 	}
 
 	// Drain in-flight audit-recording goroutines before closing the DB pool.