feat: add inbox-direct supplier invoice creation from inbox items (#558)

* feat: add inbox-direct supplier invoice creation from inbox items

- Implemented `gnubok_create_supplier_invoice_from_inbox` tool in the MCP server for creating supplier invoices directly from inbox items.
- Enhanced the input schema to include `inbox_item_id` and `document_id` for direct booking.
- Added logic to validate inbox items and link documents to journal entries during the commit process.
- Introduced `commitCreateSupplierInvoiceFromInbox` function to handle the creation and linking of supplier invoices.
- Added unit tests to cover various scenarios including happy path, idempotency, error handling, and rollbacks.
- Updated database migration to extend the `pending_operations` table to include the new operation type.

* fix: extend CHECK constraint to include create_supplier_invoice_from_inbox operation

* feat: add validation for financial fields in supplier invoice creation from inbox

supabase/migrations/20260522120000_pending_operations_add_create_supplier_invoice_from_inbox.sql

@@ -0,0 +1,61 @@
+-- Expand pending_operations.operation_type to include
+-- create_supplier_invoice_from_inbox.
+--
+-- The MCP tool gnubok_create_supplier_invoice_from_inbox already stages with
+-- this operation_type (extensions/general/mcp-server/server.ts) and the risk
+-- tier is set to 'medium' in lib/pending-operations/risk-tiers.ts, but the
+-- CHECK constraint never got updated — so every call from Claude / the MCP
+-- client failed with check_violation at INSERT time, before reaching the
+-- dispatcher.
+--
+-- This migration extends the CHECK constraint to allow the value. The
+-- corresponding commit executor (commitCreateSupplierInvoiceFromInbox in
+-- lib/pending-operations/commit.ts) is added in the same change so the
+-- dispatcher can route the op end-to-end.
+
+ALTER TABLE public.pending_operations
+  DROP CONSTRAINT IF EXISTS pending_operations_operation_type_check;
+
+ALTER TABLE public.pending_operations
+  ADD CONSTRAINT pending_operations_operation_type_check
+  CHECK (operation_type IN (
+    -- Phase 0: original 7 op types
+    'categorize_transaction',
+    'create_customer',
+    'create_invoice',
+    'mark_invoice_paid',
+    'send_invoice',
+    'mark_invoice_sent',
+    'match_transaction_invoice',
+    -- Stream 1 Phase 1: bookkeeping period operations
+    'close_period',
+    'lock_period',
+    'unlock_period',
+    'set_opening_balances',
+    'run_year_end',
+    'run_currency_revaluation',
+    -- Stream 1 Phase 1: SIE import (export is read-only)
+    'import_sie',
+    -- Stream 1 Phase 1: voucher gap explanations
+    'explain_voucher_gap',
+    -- Stream 1 Phase 1: transaction reversal
+    'uncategorize_transaction',
+    -- Stream 1 Phase 1: supplier invoice lifecycle
+    'approve_supplier_invoice',
+    'credit_supplier_invoice',
+    -- Stream 1 Phase 1: invoice operations beyond simple create/send
+    'credit_invoice',
+    'convert_invoice',
+    -- Phase 3: manual transaction ingestion + document attachment
+    'create_transaction',
+    'attach_document_to_transaction',
+    -- Phase 4: arbitrary-line bookkeeping primitives
+    'create_voucher',
+    'correct_entry',
+    -- Phase 5: supplier CRUD
+    'create_supplier',
+    -- Phase 5 (this migration): inbox → supplier invoice conversion
+    'create_supplier_invoice_from_inbox'
+  ));
+
+NOTIFY pgrst, 'reload schema';