fix(canvas): add missing budgetLimit/budget_limit to test fixtures, fix AuthGate mock types

The budget PR (#541) added budgetLimit: number | null as a required field
on WorkspaceNodeData and budget_limit: number | null on WorkspaceData.
Seven test fixture factories were not updated, causing tsc --noEmit to
produce 34 TS2322/TS2345 errors (runtime tests still passed because
Vitest transpiles via esbuild which strips types).

Fixes:
- canvas-events.test.ts: makeNode factory +budgetLimit: null
- canvas-events-pan.test.ts: makeNode factory +budgetLimit: null
- canvas-capabilities.test.ts: makeNodeData factory +budgetLimit: null
- canvas-topology.test.ts: makeWS factory +budget_limit: null
- canvas.test.ts: makeWS factory +budget_limit: null; two inline
  summarizeWorkspaceCapabilities args +budgetLimit: null; context-menu
  fixture +budgetLimit: null
- ProvisioningTimeout.test.tsx: makeWS factory +budget_limit: null

Also fixes 3 TS2348 errors in AuthGate.test.tsx: newer Vitest type defs
resolve ReturnType<typeof vi.fn> to Mock<Procedure|Constructable> which
TypeScript no longer considers directly callable in a vi.mock factory.
Fix: intersect the mock variables with a plain function type so both the
call expression and the mock API (mockReturnValue etc.) type-check.

tsc --noEmit: 0 errors. npm test: 722/722.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

canvas/src/components/__tests__/AuthGate.test.tsx

@@ -8,14 +8,18 @@ afterEach(() => {
 });
 
 // ── Mocks (defined before dynamic import of component) ───────────────────────
-let mockFetchSession: ReturnType<typeof vi.fn>;
-let mockRedirectToLogin: ReturnType<typeof vi.fn>;
-let mockGetTenantSlug: ReturnType<typeof vi.fn>;
+// Use a function type so TypeScript accepts the mock as callable in vi.mock factories.
+// ReturnType<typeof vi.fn> resolves to Mock<Procedure|Constructable> in newer Vitest
+// type defs, which TS no longer considers directly callable. Casting to a plain
+// function type avoids the TS2348 error while keeping full mock API (mockReturnValue etc.).
+let mockFetchSession: ((...args: unknown[]) => unknown) & ReturnType<typeof vi.fn>;
+let mockRedirectToLogin: ((...args: unknown[]) => unknown) & ReturnType<typeof vi.fn>;
+let mockGetTenantSlug: ((...args: unknown[]) => unknown) & ReturnType<typeof vi.fn>;
 
 beforeEach(() => {
-  mockFetchSession = vi.fn();
-  mockRedirectToLogin = vi.fn();
-  mockGetTenantSlug = vi.fn(() => null); // default: non-SaaS (pass-through)
+  mockFetchSession = vi.fn() as typeof mockFetchSession;
+  mockRedirectToLogin = vi.fn() as typeof mockRedirectToLogin;
+  mockGetTenantSlug = vi.fn(() => null) as typeof mockGetTenantSlug;
 });
 
 vi.mock("@/lib/auth", () => ({

canvas/src/components/__tests__/ProvisioningTimeout.test.tsx

@@ -28,6 +28,7 @@ function makeWS(overrides: Partial<WorkspaceData> & { id: string }): WorkspaceDa
     y: 0,
     collapsed: false,
     runtime: "",
+    budget_limit: null,
     ...overrides,
   };
 }

canvas/src/store/__tests__/canvas-capabilities.test.ts

@@ -22,6 +22,7 @@ function makeNodeData(overrides: Partial<WorkspaceNodeData> = {}): WorkspaceNode
     currentTask: "",
     needsRestart: false,
     runtime: "",
+    budgetLimit: null,
     ...overrides,
   };
 }

canvas/src/store/__tests__/canvas-events-pan.test.ts

@@ -34,6 +34,7 @@ function makeNode(
       currentTask: "",
       needsRestart: false,
       runtime: "",
+      budgetLimit: null,
       ...overrides,
     },
   };

canvas/src/store/__tests__/canvas-events.test.ts

@@ -31,6 +31,7 @@ function makeNode(
       currentTask: "",
       needsRestart: false,
       runtime: "",
+      budgetLimit: null,
       ...overrides,
     },
   };

canvas/src/store/__tests__/canvas-topology.test.ts

@@ -24,6 +24,7 @@ function makeWS(overrides: Partial<WorkspaceData> & { id: string }): WorkspaceDa
     y: 0,
     collapsed: false,
     runtime: "",
+    budget_limit: null,
     ...overrides,
   };
 }

canvas/src/store/__tests__/canvas.test.ts

@@ -27,6 +27,7 @@ function makeWS(overrides: Partial<WorkspaceData> & { id: string }): WorkspaceDa
     y: 0,
     collapsed: false,
     runtime: "",
+    budget_limit: null,
     ...overrides,
   };
 }
@@ -172,6 +173,7 @@ describe("summarizeWorkspaceCapabilities", () => {
       currentTask: "Reviewing docs",
       needsRestart: false,
       runtime: "claude-code",
+      budgetLimit: null,
     });
 
     expect(summary.runtime).toBe("claude-code");
@@ -197,6 +199,7 @@ describe("summarizeWorkspaceCapabilities", () => {
       currentTask: "   ",
       needsRestart: false,
       runtime: "",
+      budgetLimit: null,
     });
 
     expect(summary.runtime).toBeNull();
@@ -554,6 +557,7 @@ describe("context menu", () => {
       currentTask: "",
       needsRestart: false,
       runtime: "",
+      budgetLimit: null,
     },
   };