feat(agent-runner): enforce 4.x host-owned execution

skills/scripts/e2e/ensure-fake-provider-pipeline.mjs

@@ -522,7 +522,6 @@ async function ensurePipeline({ backendUrl, token, name, modelUuid }) {
     prompt: [{ role: "system", content: "You are a deterministic QA assistant. Reply exactly as instructed." }],
     "remove-think": false,
     "knowledge-bases": [],
-    "box-session-id-template": "{launcher_type}_{launcher_id}",
     "retrieval-top-k": 5,
     "rerank-model": "",
     "rerank-top-k": 5,

skills/scripts/e2e/pipeline-debug-chat.mjs

@@ -112,7 +112,9 @@ function parseJsonEnv(key, fallback) {
 }
 
 function positiveNumberEnv(key, fallback) {
-  const value = Number(env[key] || "");
+  const raw = env[key];
+  if (raw === undefined || raw === "") return fallback;
+  const value = Number(raw);
   return Number.isFinite(value) && value >= 0 ? value : fallback;
 }