fix(entitlements): gate paid MCP tools (send_invoice/agi_submit/vat_declaration_submit) server-side (#846)

The HTTP routes call requireCapability at every paid chokepoint, but the
MCP/agent path bypassed the paywall entirely: the three external-service
tools stage operations whose commit calls the email / Skatteverket services
directly, with no capability check. After the 2026-07-07 trial cutover a
trial-connected non-payer using the gnubok MCP connector could still send
invoice emails and file AGI/VAT.

Close the gap with two layers, mirroring the existing TOOL_SCOPE_MAP gate:

- Dispatch gate (mcp-server/server.ts): MCP_TOOL_CAPABILITY_MAP, checked
  right after the scope check, blocks a non-entitled company before any
  pending op is staged. Emits errorKind='capability_denied' telemetry.
- Commit-time gate (commitPendingOperation): PAID_OPERATION_CAPABILITY_MAP,
  checked before the atomic claim. The real external-service chokepoint —
  applies to the MCP approve tool AND the UI approval path, and closes the
  trial-connected-token window (the grant has expired by commit time). A
  blocked op stays 'pending', so it is re-approvable once the company subscribes.

Adds a transport-free capabilityBlockedError() helper (shared bilingual
copy) and locks both maps with tests (maps, dispatch gate, commit gate).
Only the three write/submit tools are gated; SKV read/local tools stay free
per the statutory carve-out. No DB/migration change; self-hosted stays all-on.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/pending-operations/__tests__/commit-capability-gate.test.ts

@@ -0,0 +1,91 @@
+/**
+ * Tests for the commit-time capability gate in commitPendingOperation.
+ *
+ * This is the twin of the MCP dispatch gate and the true external-service
+ * chokepoint: it runs BEFORE the atomic claim, so a blocked op stays 'pending'
+ * (re-approvable once the company subscribes) and an op staged DURING the trial
+ * cannot be committed once the grant expires — regardless of caller (MCP approve
+ * tool or the UI approval path).
+ */
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { eventBus } from '@/lib/events/bus'
+import { createQueuedMockSupabase } from '@/tests/helpers'
+import type { PendingOperation } from '@/types'
+
+vi.mock('@/lib/entitlements/has-capability', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('@/lib/entitlements/has-capability')>()
+  return { ...actual, hasCapability: vi.fn() }
+})
+
+import { commitPendingOperation } from '../commit'
+import { hasCapability } from '@/lib/entitlements/has-capability'
+
+const mockHasCapability = vi.mocked(hasCapability)
+
+function makePendingOp(overrides: Partial<PendingOperation>): PendingOperation {
+  return {
+    id: 'op-1',
+    user_id: 'user-1',
+    company_id: 'company-1',
+    operation_type: 'send_invoice',
+    status: 'pending',
+    title: 'test',
+    params: {},
+    preview_data: {},
+    result_data: null,
+    actor_type: 'user',
+    actor_id: null,
+    actor_label: null,
+    risk_level: 'high',
+    created_at: '2026-06-01T00:00:00Z',
+    resolved_at: null,
+    updated_at: '2026-06-01T00:00:00Z',
+    ...overrides,
+  } as PendingOperation
+}
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  eventBus.clear()
+})
+
+describe('commitPendingOperation: capability gate', () => {
+  it('blocks send_invoice when email_send is not entitled — 403, op left pending', async () => {
+    mockHasCapability.mockResolvedValue(false)
+    const { supabase } = createQueuedMockSupabase() // no responses enqueued: the claim must never run
+
+    const op = makePendingOp({ operation_type: 'send_invoice', params: { invoice_id: 'inv-1' } })
+    const result = await commitPendingOperation(supabase as never, 'user-1', 'company-1', op)
+
+    expect(result.status).toBe('failed')
+    expect(result.http_status).toBe(403)
+    expect(result.code).toBe('capability_blocked')
+    expect(mockHasCapability).toHaveBeenCalledWith(supabase, 'company-1', 'email_send')
+  })
+
+  it('blocks submit_vat_declaration when skatteverket is not entitled', async () => {
+    mockHasCapability.mockResolvedValue(false)
+    const { supabase } = createQueuedMockSupabase()
+
+    const op = makePendingOp({ operation_type: 'submit_vat_declaration', params: { period_type: 'monthly', year: 2025, period: 3 } })
+    const result = await commitPendingOperation(supabase as never, 'user-1', 'company-1', op)
+
+    expect(result.status).toBe('failed')
+    expect(result.http_status).toBe(403)
+    expect(result.code).toBe('capability_blocked')
+    expect(mockHasCapability).toHaveBeenCalledWith(supabase, 'company-1', 'skatteverket')
+  })
+
+  it('does NOT consult the gate for a free operation type', async () => {
+    mockHasCapability.mockResolvedValue(false)
+    const { supabase, enqueue } = createQueuedMockSupabase()
+    enqueue({ data: null, error: null }) // claim resolves to "already claimed" → early 409, before any executor
+
+    const op = makePendingOp({ operation_type: 'create_customer', params: { name: 'x' } })
+    const result = await commitPendingOperation(supabase as never, 'user-1', 'company-1', op)
+
+    // create_customer is not in PAID_OPERATION_CAPABILITY_MAP — the gate is skipped.
+    expect(mockHasCapability).not.toHaveBeenCalled()
+    expect(result.status).toBe('failed') // claim returned no row (409); proves we got past the gate
+  })
+})