FN-7446: handle missing planning MCP resolver results

Keep planning session creation resilient when the MCP resolver test seam returns no shaped result.

- Add a planning MCP resolution helper that defaults malformed resolver output to an empty server list.
- Cover both non-streaming and streaming planning sessions when MCP resolution returns undefined.
- Update the shared engine mock to return the full empty MCP resolver shape.
- Add a patch changeset for the published CLI package.

Files changed:
 .changeset/fn-7446-planning-mcp-resolver.md        |  7 +++++
 .../src/__tests__/mcp-lane-forwarding.test.ts      | 35 +++++++++++++++++++++-
 packages/dashboard/src/planning.ts                 | 18 +++++++++--
 packages/dashboard/src/test/mockCoreEngine.ts      |  4 +--
 4 files changed, 59 insertions(+), 5 deletions(-)

Fusion-Task-Id: FN-7446

Fusion-Task-Lineage: 998c30d2-2bed-4d25-b49f-3475048d6c07

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-7446-planning-mcp-resolver.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Prevent Planning Mode sessions from failing when MCP resolution returns no shaped result.
+category: fix
+dev: Dashboard planning lanes now default malformed MCP resolver output to an empty server set while preserving MCP forwarding.

packages/dashboard/src/__tests__/mcp-lane-forwarding.test.ts

@@ -56,7 +56,7 @@ vi.mock("../planning-board-tools.js", () => ({
   createPlanningBoardTools: vi.fn(() => []),
 }));
 
-import { __resetPlanningState, createSession } from "../planning.js";
+import { __resetPlanningState, createSession, createSessionWithAgent, planningStreamManager } from "../planning.js";
 import { resolveManualAiPromptMcpServers } from "../routes.js";
 import { createMissionInterviewAgent } from "../mission-interview.js";
 import { createTargetInterviewAgent } from "../milestone-slice-interview.js";
@@ -82,6 +82,39 @@ describe("dashboard MCP lane forwarding", () => {
     }));
   });
 
+  it("defaults an undefined MCP resolver result to empty servers for non-streaming planning", async () => {
+    resolveMcpServersForStoreMock.mockResolvedValueOnce(undefined as never);
+
+    await createSession("127.0.0.1", "Build without MCP", {} as never, "/tmp/fusion-dashboard-test");
+
+    expect(createFnAgentMock).toHaveBeenCalledWith(expect.objectContaining({
+      tools: "readonly",
+      allowMcpToolsInReadonly: true,
+      mcpServers: [],
+    }));
+  });
+
+  it("defaults an undefined MCP resolver result to empty servers for streaming planning", async () => {
+    resolveMcpServersForStoreMock.mockResolvedValueOnce(undefined as never);
+
+    const sessionId = await createSessionWithAgent(
+      "127.0.0.1",
+      "Stream without MCP",
+      "/tmp/fusion-dashboard-test",
+      {} as never,
+    );
+
+    const startInitialTurn = planningStreamManager.consumeInitialTurn(sessionId);
+    expect(startInitialTurn).toBeTypeOf("function");
+    startInitialTurn?.();
+
+    await vi.waitFor(() => expect(createFnAgentMock).toHaveBeenCalledWith(expect.objectContaining({
+      tools: "readonly",
+      allowMcpToolsInReadonly: true,
+      mcpServers: [],
+    })));
+  });
+
   it("resolves materialized MCP servers for manual AI-prompt workflow steps", async () => {
     const store = {} as never;
 

packages/dashboard/src/planning.ts

@@ -61,9 +61,23 @@ type AgentResult = any;
 type SkillPluginRunner = Parameters<typeof buildSessionSkillContextSync>[3];
 
 const PLANNING_BUILTIN_WEB_TOOLS = ["WebSearch", "WebFetch"] as const;
+type PlanningMcpServers = Awaited<ReturnType<typeof resolveMcpServersForStore>>["servers"];
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 let createFnAgent: any = engineCreateFnAgent;
 
+async function resolvePlanningMcpServers(store: TaskStore): Promise<PlanningMcpServers> {
+  const resolved = await resolveMcpServersForStore(store);
+  /*
+  FNXC:McpConfig 2026-07-02-13:45:
+  Planning lanes must forward shaped MCP server arrays, while dashboard route-test mocks may omit the resolver result entirely.
+  Default only malformed test-seam output to an empty in-memory set so configured servers and secret-bearing materialized fields are never logged or persisted here.
+  */
+  if (!resolved || !Array.isArray(resolved.servers)) {
+    return [];
+  }
+  return resolved.servers;
+}
+
 // ── Notification Integration ────────────────────────────────────────────
 //
 // The planning module sends "planning-awaiting-input" notifications when an
@@ -1076,7 +1090,7 @@ export async function createSession(
     builtinToolsAllowlist: [...PLANNING_BUILTIN_WEB_TOOLS],
     // FNXC:McpConfig 2026-06-25-22:31: Planning/chat session creation resolves trusted MCP servers through the dashboard-scoped store and forwards only the materialized in-memory set to the engine runtime guard.
     // FNXC:McpConfig 2026-06-29-00:00: Planning sessions are intentionally read-only but still need configured MCP documentation/context tools; opt in at the session boundary while preserving engine-side namespacing, filtering, wrappers, and disposal.
-    mcpServers: (await resolveMcpServersForStore(store)).servers,
+    mcpServers: await resolvePlanningMcpServers(store),
     allowMcpToolsInReadonly: true,
     customTools: [
       ...createPlanningBoardTools(store),
@@ -1670,7 +1684,7 @@ async function createPlanningAgent(
     builtinToolsAllowlist: [...PLANNING_BUILTIN_WEB_TOOLS],
     // FNXC:McpConfig 2026-06-25-22:31: Streaming planning uses the same dashboard-scoped MCP resolution seam as non-streaming planning so no planning lane silently drops enabled servers.
     // FNXC:McpConfig 2026-06-29-00:00: Streaming planning uses the explicit read-only MCP opt-in; non-planning read-only lanes remain denied unless they set the same reviewed policy flag.
-    mcpServers: (await resolveMcpServersForStore(store)).servers,
+    mcpServers: await resolvePlanningMcpServers(store),
     allowMcpToolsInReadonly: true,
     customTools: [
       ...createPlanningBoardTools(store),

packages/dashboard/src/test/mockCoreEngine.ts

@@ -66,8 +66,8 @@ export function createEngineMock(overrides: AnyModule = {}): AnyModule {
     */
     createChatTaskDocumentTools: vi.fn(() => []),
     createChatArtifactTools: vi.fn(() => []),
-    // FNXC:McpConfig 2026-07-02-00:00: Planning/mission route tests share this engine mock; MCP resolution must return a shaped empty server set so readonly session creation can proceed without importing real engine stores.
+    // FNXC:McpConfig 2026-07-02-13:45: Planning/mission route tests share this engine mock; MCP resolution must return the full shaped empty result so readonly session creation can proceed without importing real engine stores.
-    resolveMcpServersForStore: vi.fn(async () => ({ servers: [] })),
+    resolveMcpServersForStore: vi.fn(async () => ({ servers: [], errors: [] })),
     ...overrides,
   });
 }