Wire evidence-describer worker config in bootstrap

The rebase onto main split the evidence-describer config into two: an
LLMAgentConfig under agents.evidence-describer and a worker-tuning
EvidenceDescriberConfig (Interval, StaleAfter, MaxConcurrency) at the
top level. Bootstrap was only populating the LLM half, leaving Interval
at zero — which panics the probod boot with "non-positive interval for
NewTicker" when the evidence description worker starts. Add the missing
fields with the same defaults main uses.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/bootstrap/builder.go

@@ -225,6 +225,11 @@ func (b *Builder) Build() (*probod.FullConfig, error) {
 			ESign: probod.ESignConfig{
 				TSAURL: b.getEnvOrDefault("ESIGN_TSA_URL", "http://timestamp.digicert.com"),
 			},
+			EvidenceDescriber: probod.EvidenceDescriberConfig{
+				Interval:       b.getEnvIntOrDefault("EVIDENCE_DESCRIBER_INTERVAL", 10),
+				StaleAfter:     b.getEnvIntOrDefault("EVIDENCE_DESCRIBER_STALE_AFTER", 300),
+				MaxConcurrency: b.getEnvIntOrDefault("EVIDENCE_DESCRIBER_MAX_CONCURRENCY", 10),
+			},
 			Branding: b.getEnvBoolOrDefault("BRANDING", true),
 		},
 	}