fix(dashboard-agent): read the report's untrustworthy reason under its current name

`curateReport` still read `facts.staleReason`, renamed to `untrustworthyReason`
in dc3b50260 and split into telemetry_stale / telemetry_absent / flow_unmeasured.
The read had been undefined since, so the agent got "untrustworthy" with no why,
and the prompt still told it every such case was stale telemetry.

`facts` is `z.record(z.unknown())`, so nothing typechecked the key. The new test
goes presenter -> reports route JSON -> curateReport without naming a facts key
on the way in, and asserts curation carries every key the presenter emits.

apps/webapp/test/reportCurationTrust.test.ts

@@ -0,0 +1,81 @@
+import { curateReport } from "@internal/dashboard-agent/tool-curation";
+import { describe, expect, it } from "vitest";
+import { interpret, type HealthInput } from "~/presenters/v3/reports/health/health";
+import { reportResponse } from "~/presenters/v3/reports/reportsApi.server";
+
+/**
+ * The real chain the agent's `get_report` runs: the health presenter builds the view model, the
+ * reports route serializes it as `format=json`, and the agent curates that body. Nothing here
+ * names a `facts` key on the way in, so a producer/consumer rename fails instead of passing.
+ */
+async function curatedFacts(input: HealthInput): Promise<Record<string, unknown>> {
+  const body = await reportResponse(interpret(input), "json").json();
+  return curateReport(body).facts as Record<string, unknown>;
+}
+
+const HEALTHY: HealthInput = {
+  scope: "prod",
+  period: "last 1h",
+  baselineLabel: "vs your 7d normal",
+  generatedAt: "2026-07-20T12:00:00.000Z",
+  windowMinutes: 60,
+  flowSource: "queue_metrics_v1",
+  pending: { now: 84, normal: 120, series: [110, 96, 88, 90, 84], estimated: false },
+  startLatency: { p95Ms: 6000, normalP95Ms: 7000, series: [6500, 6200, 6000, 5900, 6000] },
+  throughput: {
+    finishedPerMin: 1000,
+    completedPerMin: 1000,
+    triggeredPerMin: 1000,
+    normalTriggeredPerMin: 1000,
+  },
+  failures: { rate: 0.009, normalRate: 0.011, series: [0.01, 0.009, 0.009] },
+  duration: { p95Ms: 1100, normalP95Ms: 1180 },
+  liveness: { telemetryAgeMs: 2000 },
+  flowEvidence: {
+    runningSeries: [40, 45, 50, 48, 44],
+    envLimit: 100,
+    throttledShare: 0,
+    worstQueue: null,
+    dlqDelta: 0,
+  },
+};
+
+describe("the agent's curated report keeps the reason its numbers can't be trusted", () => {
+  it("carries telemetry_stale", async () => {
+    const facts = await curatedFacts({ ...HEALTHY, liveness: { telemetryAgeMs: 30 * 60_000 } });
+    expect(facts.trustworthy).toBe(false);
+    expect(facts.untrustworthyReason).toBe("telemetry_stale");
+  });
+
+  it("carries telemetry_absent", async () => {
+    const facts = await curatedFacts({ ...HEALTHY, liveness: { telemetryAgeMs: null } });
+    expect(facts.trustworthy).toBe(false);
+    expect(facts.untrustworthyReason).toBe("telemetry_absent");
+  });
+
+  it("carries flow_unmeasured", async () => {
+    const facts = await curatedFacts({
+      ...HEALTHY,
+      pending: { now: 0, series: [], estimated: true, availability: "unknown" },
+    });
+    expect(facts.trustworthy).toBe(false);
+    expect(facts.untrustworthyReason).toBe("flow_unmeasured");
+  });
+
+  it("states no reason on a trustworthy report", async () => {
+    const facts = await curatedFacts(HEALTHY);
+    expect(facts.trustworthy).toBe(true);
+    expect(facts.untrustworthyReason).toBeUndefined();
+  });
+
+  it("carries every fact key the presenter emits, so the next rename fails here", async () => {
+    const emitted = interpret(HEALTHY).facts;
+    const curated = await curatedFacts(HEALTHY);
+    // `telemetry` is deliberately dropped: `trustworthy` + the reason already say what the agent acts on.
+    const dropped = new Set(["telemetry"]);
+    for (const key of Object.keys(emitted)) {
+      if (dropped.has(key)) continue;
+      expect(Object.keys(curated)).toContain(key);
+    }
+  });
+});

internal-packages/dashboard-agent/package.json

@@ -7,6 +7,7 @@
   "type": "module",
   "exports": {
     ".": "./src/index.ts",
+    "./tool-curation": "./src/tool-curation.ts",
     "./tool-schemas": "./src/tool-schemas.ts",
     "./prompt-prefix": "./src/prompt-prefix.ts"
   },

internal-packages/dashboard-agent/src/__snapshots__/prompt-prefix.test.ts.snap

@@ -4,8 +4,8 @@ exports[`the prefix stays inside its budget > matches the committed measurement
 {
   "assistant": {
     "prompt": {
-      "chars": 19266,
-      "estimatedTokens": 4817,
+      "chars": 19285,
+      "estimatedTokens": 4821,
     },
     "tools": {
       "chars": 38555,
@@ -13,15 +13,15 @@ exports[`the prefix stays inside its budget > matches the committed measurement
       "estimatedTokens": 9639,
     },
     "total": {
-      "chars": 57822,
-      "estimatedTokens": 14456,
-      "fingerprint": "f6751f8f",
+      "chars": 57841,
+      "estimatedTokens": 14460,
+      "fingerprint": "52bee164",
     },
   },
   "code": {
     "prompt": {
-      "chars": 22021,
-      "estimatedTokens": 5505,
+      "chars": 22040,
+      "estimatedTokens": 5510,
     },
     "tools": {
       "chars": 41564,
@@ -29,9 +29,9 @@ exports[`the prefix stays inside its budget > matches the committed measurement
       "estimatedTokens": 10391,
     },
     "total": {
-      "chars": 63586,
-      "estimatedTokens": 15897,
-      "fingerprint": "6432d8b0",
+      "chars": 63605,
+      "estimatedTokens": 15901,
+      "fingerprint": "037bcfc3",
     },
   },
 }

internal-packages/dashboard-agent/src/tool-curation.ts

@@ -189,7 +189,7 @@ export function curateReport(data: unknown) {
     })),
     facts: {
       trustworthy: facts.trustworthy,
-      staleReason: facts.staleReason,
+      untrustworthyReason: facts.untrustworthyReason,
       flowSource: facts.flowSource,
       pendingEstimated: facts.pendingEstimated,
       throughput: facts.throughput,

internal-packages/dashboard-agent/src/tool-schemas.ts

@@ -458,7 +458,7 @@ Knowing where the user is, and taking them places:
 
 Is anything wrong?:
 - For "is anything wrong", "how is prod doing", "is everything healthy", start with get_report. It grades flow, execution, and liveness together, which is a better first answer than any single query.
-- If the report's facts.trustworthy is false, the underlying telemetry is stale: say the data can't be trusted right now and what would confirm it. Do NOT diagnose a cause or recommend an action off untrusted numbers.
+- If the report's facts.trustworthy is false, say why from facts.untrustworthyReason (telemetry_stale, telemetry_absent or flow_unmeasured) and what would confirm it. Do NOT diagnose a cause or recommend an action off untrusted numbers.
 - When the report points at flow (runs not starting), follow up with get_queue on the queue it names to see depth, wait time, and throttling. When it points at execution, follow up with list_errors / get_run_trace.
 - When something started failing at a particular time, check list_deploys for a deploy in that window, and correlate_version on a failing run to see the exact commit and pull request it ran.