Harden common third party enricher edge cases

Reject oversized logo responses instead of silently truncating them,
which could persist corrupt image bytes as a valid logo.

Tighten ownership substring matching with a length-ratio guard so a
short label root no longer attributes unrelated domains to a vendor.

Render the worker confidence threshold when set to zero by testing
against nil, so an explicit "accept all" value is not dropped by Helm's
falsy-numeric truthiness.

Sanitize and bound per-agent error text before persisting it to the
enrichment metadata column to avoid leaking unbounded internal detail.

Signed-off-by: Émile Ré <emile@probo.com>

contrib/helm/charts/probo/templates/deployment.yaml

@@ -416,7 +416,7 @@ spec:
             - name: COMMON_THIRD_PARTY_ENRICHMENT_AGENT_MAX_TURNS
               value: {{ .Values.probo.commonThirdPartyEnrichmentWorker.agentMaxTurns | quote }}
             {{- end }}
-            {{- if .Values.probo.commonThirdPartyEnrichmentWorker.confidenceThreshold }}
+            {{- if ne .Values.probo.commonThirdPartyEnrichmentWorker.confidenceThreshold nil }}
             - name: COMMON_THIRD_PARTY_ENRICHMENT_CONFIDENCE_THRESHOLD
               value: {{ .Values.probo.commonThirdPartyEnrichmentWorker.confidenceThreshold | quote }}
             {{- end }}