fix: end-to-end certificate lifecycle bugs + integration test environment

Fixes 12 production bugs preventing the full issuance→deployment flow
from working with ACME (Pebble/Let's Encrypt) and step-ca issuers:

ACME connector (acme.go):
- Save orderURI before WaitOrder overwrites it (Go crypto/acme bug)
- Add CreateOrderCert fallback via WaitOrder+FetchCert
- Remove defer-reset in ValidateConfig that caused nil pointer panic
- Add Insecure TLS option for self-signed ACME servers (Pebble)

step-ca connector (stepca.go, jwe.go):
- Real JWE provisioner key loading + decryption (was using ephemeral keys)
- Fix JWT audience (/1.0/sign), sha claim (key fingerprint), kid header
- Custom root CA trust via RootCertPath config
- Remove hardcoded 90-day validity default (let step-ca decide)

NGINX target connector (nginx.go):
- Use sh -c for validate/reload commands (shell interpretation)
- Use filepath.Dir instead of fragile string slicing
- Add private key file writing (agent-mode keys were never deployed)
- Make chain_path write conditional

Server/service layer:
- TriggerRenewalWithActor now creates actual Job records (was no-op)
- createDeploymentJobs falls back to DB query when cert.TargetIDs empty
- ProcessPendingJobs skips agent-routed deployment jobs
- Agent cert pickup path parsing: len(parts)<4 → len(parts)<3
- Health/ready/auth-info endpoints bypass auth middleware
- Write timeout 15s→120s for ACME issuance
- Cert fingerprint computed on CSR submission

Integration test environment (deploy/test/):
- 10-phase test script covering Local CA, ACME, step-ca, revocation,
  discovery, renewal, and API spot checks
- Docker Compose with 7 containers (server, agent, postgres, nginx,
  pebble, challtestsrv, step-ca) on isolated network
- TLS verification checks SAN (not just Subject CN) for modern CA compat

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/service/job.go

@@ -54,6 +54,16 @@ func (s *JobService) ProcessPendingJobs(ctx context.Context) error {
 
 	// Process each job
 	for _, job := range pendingJobs {
+		// Skip deployment jobs that have an agent_id — those are meant for agent
+		// pickup via GetPendingWork(), not server-side processing. The server should
+		// only process deployment jobs without an agent (legacy/serverless targets).
+		if job.Type == domain.JobTypeDeployment && job.AgentID != nil && *job.AgentID != "" {
+			s.logger.Debug("skipping agent-routed deployment job",
+				"job_id", job.ID,
+				"agent_id", *job.AgentID)
+			continue
+		}
+
 		if err := s.processJob(ctx, job); err != nil {
 			s.logger.Error("failed to process job",
 				"job_id", job.ID,