test: prove Codex structured and select semantics

Assert exact skill/mention paths survive turn/steer and compile-check that generated request_user_input questions have no multi-select field while MCP array elicitation remains multi-select.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: f047b252-1029-4093-9a8e-53456b7dd740

Author: SlowGreekMSFT

apps/server/src/provider/Layers/CodexAdapter.test.ts

@@ -33,6 +33,7 @@ import * as Schema from "effect/Schema";
 import * as Scope from "effect/Scope";
 import * as Stream from "effect/Stream";
 import * as CodexErrors from "effect-codex-app-server/errors";
+import * as EffectCodexSchema from "effect-codex-app-server/schema";
 
 import { ServerConfig } from "../../config.ts";
 import { ServerSettingsService } from "../../serverSettings.ts";
@@ -58,6 +59,9 @@ const asThreadId = (value: string): ThreadId => ThreadId.make(value);
 const asTurnId = (value: string): TurnId => TurnId.make(value);
 const asEventId = (value: string): EventId => EventId.make(value);
 const asItemId = (value: string): ProviderItemId => ProviderItemId.make(value);
+const generatedRequestUserInputSupportsMultiSelect: "multiSelect" extends keyof EffectCodexSchema.ToolRequestUserInputParams__ToolRequestUserInputQuestion
+  ? true
+  : false = false;
 
 class FakeCodexRuntime implements CodexSessionRuntimeShape {
   private readonly eventQueue = Effect.runSync(Queue.unbounded<ProviderEvent>());
@@ -1145,6 +1149,7 @@ lifecycleLayer("CodexAdapterLive lifecycle", (it) => {
         const events = Array.from(yield* Fiber.join(eventsFiber));
         NodeAssert.equal(events[0]?.type, "user-input.requested");
         if (events[0]?.type === "user-input.requested") {
+          NodeAssert.equal(generatedRequestUserInputSupportsMultiSelect, false);
           NodeAssert.equal(events[0].requestId, "req-user-input-1");
           NodeAssert.equal(events[0].payload.questions[0]?.id, "sandbox_mode");
           NodeAssert.equal(events[0].payload.questions[0]?.multiSelect, false);

apps/server/src/provider/Layers/CodexAdapter.ts

@@ -374,6 +374,8 @@ function toUserInputQuestions(questions: ReadonlyArray<CodexToolUserInputQuestio
         options,
         allowOther: question.isOther ?? options.length === 0,
         isSecret: question.isSecret ?? false,
+        // The generated request_user_input question has no multi-select field.
+        // MCP elicitation array schemas are projected separately with multiSelect=true.
         multiSelect: false,
       };
     })

apps/server/src/provider/Layers/CodexSessionRuntime.test.ts

@@ -287,14 +287,38 @@ describe("Codex turn steering", () => {
         threadId: "provider-thread-1",
         expectedTurnId: "turn-active",
         clientUserMessageId: "message-2",
-        turnInput: [{ type: "text", text: "Use the other approach" }],
+        turnInput: [
+          { type: "text", text: "Use the other approach" },
+          {
+            type: "skill",
+            name: "frontend-design",
+            path: "/skills/frontend-design/SKILL.md",
+          },
+          {
+            type: "mention",
+            name: "App.tsx",
+            path: "apps/web/src/App.tsx",
+          },
+        ],
       });
 
       NodeAssert.deepStrictEqual(params, {
         threadId: "provider-thread-1",
         expectedTurnId: "turn-active",
         clientUserMessageId: "message-2",
-        input: [{ type: "text", text: "Use the other approach" }],
+        input: [
+          { type: "text", text: "Use the other approach" },
+          {
+            type: "skill",
+            name: "frontend-design",
+            path: "/skills/frontend-design/SKILL.md",
+          },
+          {
+            type: "mention",
+            name: "App.tsx",
+            path: "apps/web/src/App.tsx",
+          },
+        ],
       });
     }),
   );

docs/operations/workplace-fork.md

@@ -43,6 +43,8 @@ Typed app-server callbacks cover MCP elicitation, granular permission approval,
 
 Codex question metadata is preserved for optionless free text, Other answers, secrets, mixed question sets, and MCP multi-select fields. Secret answers use a password control and are never rendered as visible composer text.
 
+The generated `item/tool/requestUserInput` question type has no multi-select field and is intentionally projected as single-select. Multi-select is native for MCP elicitation array schemas and is preserved there; a compile-time schema assertion guards this protocol distinction.
+
 Composer `$skill` selections and local markdown file links are resolved against the active provider snapshot and sent as native Codex `skill` and `mention` user-input entries. The original text remains intact for display and non-Codex providers; disabled/unknown skills and external links are not promoted to trusted structured inputs.
 
 The command palette exposes native MCP management for an active Codex thread. Inventory, OAuth initiation/completion notifications, resource reads, direct tool invocation, server reload, and per-server enablement all use the shared app-server connection. Direct invocation requires an explicit per-server trust confirmation each time; T3 does not persist that confirmation or bypass Codex approval policy.