refactor: consolidate extension system to general-only with manifest-driven architecture

- Remove all sector-specific extensions (construction, ecommerce, export,
  hotel, restaurant, tech) — only general-purpose extensions remain
- Move NE-bilaga and SRU export from extensions to core reports (lib/reports/)
- Move moms-box-mapping from extensions/export/shared to lib/vat/
- Replace per-extension API routes with catch-all dispatcher
  (app/api/extensions/ext/[...path]/route.ts)
- Add manifest.json for each extension with metadata, env vars, and deps
- Add api-routes.ts pattern for extension-defined API endpoints
- Add code generation scripts (generate-extension-registry, create-extension)
- Add extensions.config.json for opt-in extension loading
- Add extensions.schema.json for config validation
- Add email service interface with noop default (lib/email/service.ts)
- Add CI workflow (core-build.yml) to verify core builds with zero extensions
- Add migration 045: expand account_type CHECK for untaxed_reserves
- Update CLAUDE.md with comprehensive extension system documentation
- Update all report engines and bookkeeping services for new imports
- Clean up extensions.schema.json to only list existing extensions

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

lib/extensions/loader.ts

@@ -1,47 +1,14 @@
 import { extensionRegistry } from './registry'
-import { receiptOcrExtension } from '@/extensions/general/receipt-ocr'
-import { aiCategorizationExtension } from '@/extensions/general/ai-categorization'
-import { pushNotificationsExtension } from '@/extensions/general/push-notifications'
-import { aiChatExtension } from '@/extensions/general/ai-chat'
-import { invoiceInboxExtension } from '@/extensions/general/invoice-inbox'
-import { calendarExtension } from '@/extensions/general/calendar'
-import { userDescriptionMatchExtension } from '@/extensions/general/user-description-match'
-import { euSalesListExtension } from '@/extensions/export/eu-sales-list'
-import { vatMonitorExtension } from '@/extensions/export/vat-monitor'
-import { intrastatExtension } from '@/extensions/export/intrastat'
-import { currencyReceivablesExtension } from '@/extensions/export/currency-receivables'
-import type { Extension } from './types'
-
-import { enableBankingExtension } from '@/extensions/general/enable-banking'
-
-/**
- * Explicit list of first-party extensions.
- *
- * Next.js bundling requires static imports — no dynamic filesystem scanning.
- * Add extensions here as they are built.
- */
-const FIRST_PARTY_EXTENSIONS: Extension[] = [
-  receiptOcrExtension,
-  aiCategorizationExtension,
-  pushNotificationsExtension,
-  aiChatExtension,
-  invoiceInboxExtension,
-  calendarExtension,
-  userDescriptionMatchExtension,
-  enableBankingExtension,
-
-  // ── Export sector ──────────────────────────────────────────
-  euSalesListExtension,
-  vatMonitorExtension,
-  intrastatExtension,
-  currencyReceivablesExtension,
-]
+import { FIRST_PARTY_EXTENSIONS } from './_generated/extension-list'
 
 let loaded = false
 
 /**
- * Load and register all first-party extensions.
+ * Load and register all configured extensions.
  * Idempotent — safe to call multiple times.
+ *
+ * Extensions are controlled by extensions.config.json.
+ * Run `npm run setup:extensions` to regenerate after config changes.
  */
 export function loadExtensions(): void {
   if (loaded) return