Keep dry-run discovery resilient

Report inbox discovery failures per recipient during dry runs so one
bad actor lookup does not hide the rest of the benchmark plan.

#795 (comment)

Assisted-by: Codex:gpt-5.5

Author: dahlia

packages/cli/src/bench/action.test.ts

@@ -169,6 +169,45 @@ test("runBench - dry run prints a plan and sends nothing", async () => {
   }
 });
 
+test("runBench - dry run reports inbox discovery failures and continues", async () => {
+  const target = await spawnBenchmarkTarget();
+  try {
+    const file = await writeSuite(`version: 1
+target: ${target.url.href}
+scenarios:
+  - name: inbox-shared
+    type: inbox
+    recipient:
+      - "${new URL("/users/missing", target.url).href}"
+      - "${new URL("/users/alice", target.url).href}"
+    inbox: shared
+    load: { concurrency: 2 }
+    duration: 250ms
+`);
+    let code = -1;
+    let output = "";
+    await runBench(command({ scenario: file, dryRun: true }), {
+      exit: (c) => {
+        code = c;
+      },
+      writeOutput: (c) => {
+        output = c;
+        return Promise.resolve();
+      },
+      log: () => {},
+    });
+    assert.strictEqual(code, 0);
+    assert.match(output, /\/users\/missing/);
+    assert.match(output, /discovery failed/);
+    assert.match(output, /\/users\/alice/);
+    assert.match(output, /\/inbox/);
+    assert.match(output, /No benchmark load was sent/);
+    assert.ok(!target.requests().some((r) => r.method === "POST"));
+  } finally {
+    await target.close();
+  }
+});
+
 test("runBench - unsafe override requires an explicit CLI target", async () => {
   const file = await writeSuite(`version: 1
 target: https://example.com

packages/cli/src/bench/action.ts

@@ -4,7 +4,11 @@ import process from "node:process";
 import { getContextLoader, getDocumentLoader } from "../docloader.ts";
 import { buildFleet } from "./actor/fleet.ts";
 import type { BenchCommand } from "./command.ts";
-import { discoverInbox, selectInbox } from "./discovery/discover.ts";
+import {
+  type DiscoveredInbox,
+  discoverInbox,
+  selectInbox,
+} from "./discovery/discover.ts";
 import {
   buildReport,
   buildScenarioResult,
@@ -398,11 +402,19 @@ async function describeInboxDiscoveryPlan(
 ): Promise<string[]> {
   const lines: string[] = [];
   for (const recipient of scenario.recipients) {
-    const discovered = await discoverInbox(recipient, {
-      documentLoader: context.documentLoader,
-      contextLoader: context.contextLoader,
-      allowPrivateAddress: context.allowPrivateAddress,
-    });
+    let discovered: DiscoveredInbox;
+    try {
+      discovered = await discoverInbox(recipient, {
+        documentLoader: context.documentLoader,
+        contextLoader: context.contextLoader,
+        allowPrivateAddress: context.allowPrivateAddress,
+      });
+    } catch (error) {
+      lines.push(
+        `  recipient ${recipient}: discovery failed (${describeError(error)})`,
+      );
+      continue;
+    }
     const inbox = selectInbox(discovered, scenario.inbox);
     lines.push(
       `  recipient ${recipient}: actor ${discovered.actorUri.href}, ` +
@@ -419,6 +431,10 @@ async function describeInboxDiscoveryPlan(
   return lines;
 }
 
+function describeError(error: unknown): string {
+  return error instanceof Error ? error.message : String(error);
+}
+
 function describeWebFingerPlan(
   scenario: ResolvedScenario,
   target: URL,