fix(j5): a project with no agents yet lists its people instead of failing

Listing a project that exists but has no ledger yet failed with a placement
error. The glossary also still said only a person steers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Jacksondr5

apps/server/src/j5/a2a/mcp/handlers.test.ts

@@ -60,7 +60,11 @@ import {
 } from "../HomeRegistrar.ts";
 import { A2ALedger } from "../LedgerService.ts";
 import { PeerDirectory, noneLayer as peerDirectoryNoneLayer } from "../PeerDirectory.ts";
-import { ParticipantPlacementService, PlacementStorageError } from "../PlacementService.ts";
+import {
+  ParticipantPlacementService,
+  PlacementProjectNotFoundError,
+  PlacementStorageError,
+} from "../PlacementService.ts";
 import { A2AHomeMembershipStateError, A2ASendService } from "../SendService.ts";
 import { SpawnCompositionService } from "../SpawnCompositionService.ts";
 import { ThreadRegistration } from "../ThreadRegistration.ts";
@@ -682,6 +686,7 @@ it.effect("lists active and archived agent titles with one ambient shell snapsho
     });
     const callerParticipantId = ParticipantId.make("agent:j5:mcp-directory:caller");
     const otherLedgerProjectId = LedgerProjectId.make("ledger:j5:mcp-directory:other");
+    const emptyLedgerProjectId = LedgerProjectId.make("ledger:j5:mcp-directory:empty");
     const elsewhereParticipantId = ParticipantId.make("agent:j5:mcp-directory:elsewhere");
     const elsewhereThreadId = ThreadId.make("thread:j5:mcp-directory:elsewhere");
     const rows = [
@@ -781,7 +786,11 @@ it.effect("lists active and archived agent titles with one ambient shell snapsho
           sendService,
           orchestrator,
           Layer.mock(ParticipantPlacementService)({
-            listParticipants: () => Effect.succeed([]),
+            // A project nobody has worked in yet has no ledger to place anything in.
+            listParticipants: (projectId) =>
+              projectId === emptyLedgerProjectId
+                ? Effect.fail(new PlacementProjectNotFoundError({ projectId }))
+                : Effect.succeed([]),
           }),
           Layer.mock(A2ADeliveryWorker)({ notify: Effect.void }),
           unusedLifecycleDependencies,
@@ -926,6 +935,11 @@ it.effect("lists active and archived agent titles with one ambient shell snapsho
       [humanParticipantId, elsewhereParticipantId],
       "another project lists its own agents, and the people",
     );
+    assert.deepStrictEqual(
+      ids(yield* list({ project_id: emptyLedgerProjectId })),
+      [humanParticipantId],
+      "a project with no agents yet lists the people",
+    );
     const gone = yield* call({ project_id: LedgerProjectId.make(missingProjectId) });
     assert.isTrue(gone.isFailure);
     assert.include(JSON.stringify(gone.encodedResult), `no project ${missingProjectId}`);

apps/server/src/j5/a2a/mcp/handlers.ts

@@ -759,9 +759,15 @@ const handlers = {
       );
       const placements = yield* ParticipantPlacementService;
       const placementByParticipant = new Map(
-        (projectId === undefined ? [] : yield* placements.listParticipants(projectId)).map(
-          (row) => [row.participantId, row] as const,
-        ),
+        (projectId === undefined
+          ? []
+          : // A project nobody has worked in yet has no ledger, so nothing is placed in it.
+            yield* placements
+              .listParticipants(projectId)
+              .pipe(
+                Effect.catchTag("PlacementProjectNotFoundError", () => Effect.succeed([])),
+              )
+        ).map((row) => [row.participantId, row] as const),
       );
       const localRows = directory
         .filter((row) => row.participant.kind !== "human" && row.projectId === projectId)

docs/j5/product/glossary.md

@@ -67,7 +67,7 @@ These entries are the distinctions the whole team must share; the glossary owns
 | delivery receipt             | The recorded fact that a message was delivered                                                                                                                | [a2a/index.md](a2a/index.md)                                                     |
 | delivery alarm               | The recorded fact that a delivery failed                                                                                                                      | [a2a/index.md](a2a/index.md)                                                     |
 | silence notice               | A platform-authored fact appended when an agent's turn ends without a reply it owed                                                                           | [a2a/index.md](a2a/index.md)                                                     |
-| queue, steer                 | The two ways a message reaches an agent mid-turn: queued behind the active turn, or steered into it. Agent deliveries queue; only a person steers, explicitly | [a2a/index.md](a2a/index.md)                                                     |
+| queue, steer                 | The two ways a message reaches an agent mid-turn: queued behind the active turn, or steered into it. Agent deliveries queue unless the sender asks for a steer or a restart | [a2a/index.md](a2a/index.md)                                                     |
 | human node                   | A person as a participant in the communication graph, keyed by person id                                                                                      | [features/inbox.md](features/inbox.md)                                           |
 
 ## Humans and attention