fix(uptime): отличать ошибки опроса от измеренных потерь Ping

lib/dashboard-probes.test.ts

@@ -19,3 +19,9 @@ test("ping observed zero and failure retain independent measurement values and s
 test("ping invalid time axis, duplicate or out of range samples cannot replace cache",()=>{
  for(const raw of [payload([sampled,sampled]),payload([{...sampled,sampledAt:"invalid"}]),payload([{...sampled,sampledAt:"2026-10-02T00:00:00Z"}]),{...payload([sampled]),rangeEndAt:start},{...payload([sampled]),rangeStartAt:undefined},payload([{...sampled,loss:101}])])assert.throws(()=>parseDashboardProbes(raw))
 })
+test("failed execution is an unknown observation, while measured 100 percent loss remains down",()=>{
+ const failed={...sampled,sampledAt:"2026-10-03T00:31:00Z",rtt:null,loss:null,status:"unknown",error:"API denied"}
+ const p=parseDashboardProbes(payload([sampled,failed])).probes[0]
+ assert.equal(p.status,"unknown");assert.equal(p.rtt,null);assert.equal(p.loss,null);assert.equal(p.observationError,"API denied");assert.equal(p.series[31],null)
+ assert.throws(()=>parseDashboardProbes(payload([{...failed,loss:100}])))
+})