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).

install-agent.sh

@@ -75,6 +75,14 @@ EXAMPLES:
           --server-url https://certctl.example.com \\
           --api-key YOUR_API_KEY
 
+CONTROL-PLANE TLS TRUST:
+    The certctl server is HTTPS-only as of v2.2. This installer does NOT copy a CA
+    bundle — the generated agent.env leaves TLS trust to the system root store by
+    default. If the server uses a private/enterprise or self-signed CA, set
+    CERTCTL_SERVER_CA_BUNDLE_PATH in the generated agent.env to point at the CA
+    bundle, or (dev only) CERTCTL_SERVER_TLS_INSECURE_SKIP_VERIFY=true. See the
+    commented block in the generated agent.env for the full menu.
+
 EOF
 }
 
@@ -322,7 +330,7 @@ setup_linux_config() {
 # Agent ID (unique identifier in the fleet)
 CERTCTL_AGENT_ID=$AGENT_ID
 
-# Control plane server URL
+# Control plane server URL (HTTPS-only as of v2.2)
 CERTCTL_SERVER_URL=$SERVER_URL
 
 # API authentication key
@@ -334,6 +342,21 @@ CERTCTL_KEYGEN_MODE=agent
 # Key storage directory (agent-side keygen)
 CERTCTL_KEY_DIR=$key_dir
 
+# ---- Control-plane TLS trust ----
+# The certctl server is HTTPS-only (v2.2+). The agent's HTTP client MUST trust the
+# server's certificate chain. Pick ONE of the approaches below:
+#
+#   1) Public CA (Let's Encrypt, DigiCert, etc.) — no config needed; system trust store works.
+#   2) Private / enterprise CA — point the agent at the CA bundle that signed the server cert:
+# CERTCTL_SERVER_CA_BUNDLE_PATH=/etc/certctl/server-ca.crt
+#
+#   3) Self-signed server cert (Helm/compose bootstrap) — same env var, just point at the
+#      extracted self-signed CA bundle (e.g. from the certctl-server-tls Kubernetes secret
+#      via: kubectl get secret certctl-server-tls -o jsonpath='{.data.ca\.crt}' | base64 -d).
+#
+#   4) Dev/eval only — disable verification entirely (NEVER do this in production):
+# CERTCTL_SERVER_TLS_INSECURE_SKIP_VERIFY=true
+
 # Logging level (debug, info, warn, error)
 # CERTCTL_LOG_LEVEL=info
 
@@ -373,7 +396,7 @@ setup_macos_config() {
 # Agent ID (unique identifier in the fleet)
 CERTCTL_AGENT_ID=$AGENT_ID
 
-# Control plane server URL
+# Control plane server URL (HTTPS-only as of v2.2)
 CERTCTL_SERVER_URL=$SERVER_URL
 
 # API authentication key
@@ -385,6 +408,21 @@ CERTCTL_KEYGEN_MODE=agent
 # Key storage directory (agent-side keygen)
 CERTCTL_KEY_DIR=$key_dir
 
+# ---- Control-plane TLS trust ----
+# The certctl server is HTTPS-only (v2.2+). The agent's HTTP client MUST trust the
+# server's certificate chain. Pick ONE of the approaches below:
+#
+#   1) Public CA (Let's Encrypt, DigiCert, etc.) — no config needed; system trust store works.
+#   2) Private / enterprise CA — point the agent at the CA bundle that signed the server cert:
+# CERTCTL_SERVER_CA_BUNDLE_PATH=$HOME/.certctl/server-ca.crt
+#
+#   3) Self-signed server cert (Helm/compose bootstrap) — same env var, just point at the
+#      extracted self-signed CA bundle (e.g. from the certctl-server-tls Kubernetes secret
+#      via: kubectl get secret certctl-server-tls -o jsonpath='{.data.ca\.crt}' | base64 -d).
+#
+#   4) Dev/eval only — disable verification entirely (NEVER do this in production):
+# CERTCTL_SERVER_TLS_INSECURE_SKIP_VERIFY=true
+
 # Logging level (debug, info, warn, error)
 # CERTCTL_LOG_LEVEL=info