feat(agent): let the single-call assistant read the ledger via read-only MCP tools (#1767)

The /chat assistant (audit Option A / rip) shipped in #1759 reading only the
company name + entity type, so it answered "jag har ingen bokföringsdata" to
every figures question ("vad är min största utgiftspost?"). It now behaves like
an MCP client: it answers over a bounded, READ-only tool loop across the same
MCP read tools the old streaming assistant had, plus an always-on company
snapshot as the backstop.

Provider-agnostic by construction, so it still runs on a local model:
- lib/ai generateText gains optional `tools` + `maxSteps`. The OpenAI-compatible
  service forwards them to the Vercel AI SDK (stopWhen: stepCountIs), which runs
  the loop; the Anthropic-family service hand-rolls a small loop against
  messages.create. Kept on the raw Anthropic SDK: no new deps, and the no-tools
  path is byte-identical, so hosted extraction/composer/etc. are unchanged.
- lib/agent/ask/ledger-tools.ts: the read slice of general.help's whitelist
  (income statement, VAT, ledgers, query_journal, reskontror, lists…) from
  agentToolRegistry, dispatched with the agent_chat actor run-turn uses. Write/
  staging + memory-write tools are excluded; readOnlyHint/destructiveHint are
  re-checked. Empty in a core-only build → snapshot-only, graceful.
- lib/agent/ask/snapshot.ts: a compact company_settings + deadlines block so a
  model that can't/won't call tools still answers status questions. Never carries
  figures (those come from the live tools).
- ask-service attaches tools + snapshot when a userId is present and uses a
  tool-aware system prompt; the route calls ensureInitialized() so the registry
  is populated and threads userId/conversationId through.

Works on Bedrock and on any local model with function-calling (Qwen). Tests:
the anthropic hand-rolled loop (tool call → result → answer, is_error handling,
step-budget forced answer), openai tool forwarding, the read-only adapter
filter, the snapshot format, and the ask-service wiring. 457 agent+ai tests
green, lint/guards clean.

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

app/api/agent/ask/__tests__/route.test.ts

@@ -2,6 +2,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest'
 import { NextResponse } from 'next/server'
 import { createMockRequest, parseJsonResponse } from '@/tests/helpers'
 
+vi.mock('@/lib/init', () => ({ ensureInitialized: vi.fn() }))
 const requireAuthMock = vi.fn()
 vi.mock('@/lib/auth/require-auth', () => ({ requireAuth: () => requireAuthMock() }))
 vi.mock('@/lib/company/context', () => ({ getActiveCompanyId: vi.fn().mockResolvedValue('company-1') }))

app/api/agent/ask/route.ts

@@ -1,5 +1,6 @@
 import { NextResponse } from 'next/server'
 import { z } from 'zod'
+import { ensureInitialized } from '@/lib/init'
 import { requireAuth } from '@/lib/auth/require-auth'
 import { getActiveCompanyId } from '@/lib/company/context'
 import { checkAgentRateLimit, agentRateLimitResponseBody } from '@/lib/rate-limits/agent'
@@ -15,16 +16,23 @@ import {
 } from '@/lib/agent/ask/persist'
 import { getErrorMessage as getUserErrorMessage } from '@/lib/errors/get-error-message'
 
+// The assistant answers over the read-only MCP tools, which are registered
+// into the agent tool registry by the mcp-server extension at load. Without
+// this the registry is empty and the assistant falls back to snapshot-only,
+// so a hosted deploy would silently lose its ledger tools.
+ensureInitialized()
+
 /**
- * POST /api/agent/ask: a single-call, provider-agnostic assistant answer.
+ * POST /api/agent/ask: a single-call, provider-agnostic assistant answer over a
+ * bounded read-only tool loop.
  *
  * Unlike POST /api/agent/invoke (the streaming Anthropic chat runtime, which
  * is gated on `assistantAvailable` and only runs on the Anthropic family),
- * this endpoint uses getAiService().generateText, so it runs on ANY configured
- * backend, including an OpenAI-compatible local model. It is therefore gated
- * on `configured`, not `assistantAvailable`. This is the replacement chat
- * surface's server side (audit Option A / rip): a page posts its context and
- * a question, gets one answer back.
+ * this endpoint answers through getAiService().generateText, so it runs on ANY
+ * configured backend, including an OpenAI-compatible local model. It is
+ * therefore gated on `configured`, not `assistantAvailable`. The service
+ * attaches the read-only MCP tools so it can fetch real figures (audit Option
+ * A / rip): a page posts its context and a question, gets one answer back.
  */
 
 const Schema = z.object({
@@ -93,6 +101,7 @@ export async function POST(request: Request): Promise<Response> {
       const result = await answerAssistantQuestion({
         supabase,
         companyId,
+        userId: user.id,
         question: parsed.data.question,
         pageContext: parsed.data.context,
         tier: parsed.data.tier,
@@ -127,6 +136,8 @@ export async function POST(request: Request): Promise<Response> {
     const result = await answerAssistantQuestion({
       supabase,
       companyId,
+      userId: user.id,
+      conversationId,
       question: parsed.data.question,
       pageContext: parsed.data.context,
       tier: parsed.data.tier,