Supp/invoice bfl errors (#390)

* feat(accounting): update accounting method validation and messaging for aktiebolag and enskild firma

* Remove AI subsystem and related code

- Deleted AI proposals and requests persistence logic from `lib/ai/proposals/persist.ts`.
- Removed re-validation logic for proposals in `lib/ai/proposals/re-validate.ts`.
- Cleaned up schemas related to AI flows in `lib/api/schemas.ts`.
- Removed AI-related fields from bookkeeping engine in `lib/bookkeeping/engine.ts`.
- Eliminated AI event types from `lib/events/types.ts`.
- Updated tests to reflect the removal of AI-related functionality in `lib/extensions/__tests__/sectors.test.ts`.
- Adjusted initialization logic in `lib/init.ts` to exclude AI proposal handler registration.
- Cleaned up transaction ingestion logic in `lib/transactions/ingest.ts` to remove AI flow checks.
- Updated helper functions in `tests/helpers.ts` to remove AI-related settings.
- Removed AI-related types and interfaces from `types/index.ts`.
- Added migration script to drop AI-related tables and settings from the database.

* fix(migrations): ensure foreign key constraint is dropped before removing AI tables

* feat(invoice-inbox): implement deterministic invoice field extraction and inbox provisioning

- Added `extract-invoice-fields.ts` for extracting fields from PDF invoices using regex and pdfjs-dist, replacing the previous AI classifier.
- Introduced `inbox-provisioning.ts` to manage company inbox addresses and rotation of inboxes using Supabase RPCs.
- Created `resend-inbound.ts` for handling inbound email events and attachments via the Resend API.
- Defined the extension manifest for the invoice inbox, specifying required environment variables and descriptions.
- Migrated database schema to remove AI-related columns and tighten the status enum in `invoice_inbox_items`.

* feat(invoice-inbox): remove AI-specific columns and tighten status enum

* fix(skattekonto): remove manual entry creation reference from transaction input

* fix(schemas): remove accounting method validation for aktiebolag in UpdateSettingsSchema

supabase/migrations/20260504120000_remove_ai_subsystem.sql

@@ -0,0 +1,38 @@
+-- Remove the AI agent subsystem (receipts v1).
+--
+-- Drops the dedicated AI tables and the per-company toggles. Code that
+-- referenced these has been deleted from lib/ai, app/api/ai, the agent-inbox
+-- UI, and the three AI extensions (invoice-inbox, inbox-smart-match,
+-- ai-agent).
+--
+-- Deliberately NOT dropped:
+--   * journal_entries.created_via and journal_entries.source_proposal_id —
+--     left as harmless dead columns. journal_entries is legally immutable
+--     under BFL 7 kap 5 §; structural changes to that table are sensitive.
+--     Defaults ('manual' / NULL) keep new inserts working without code
+--     populating these fields.
+--   * categorization_templates.source = 'ai_corrected' CHECK value — kept
+--     as a historical/audit value. Existing rows with that source remain
+--     valid; nothing new will set it.
+--   * processing_event_types CHECK enum value 'MatchProposal' /
+--     'AIProposal' / 'AIRequest' — kept as dead enum values for the same
+--     reason; no code emits them now.
+--
+-- Apply via Supabase preview branch first, never directly to production.
+
+-- journal_entries.source_proposal_id has an FK to ai_proposals
+-- (ON DELETE SET NULL — applies to row deletes, not DROP TABLE).
+-- Drop the constraint explicitly so the table drop succeeds; the
+-- column itself stays as a dead column per the note above.
+ALTER TABLE public.journal_entries
+  DROP CONSTRAINT IF EXISTS journal_entries_source_proposal_id_fkey;
+
+DROP TABLE IF EXISTS public.ai_proposals;
+DROP TABLE IF EXISTS public.ai_requests;
+DROP TABLE IF EXISTS public.ai_usage_tracking;
+
+ALTER TABLE public.company_settings
+  DROP COLUMN IF EXISTS ai_flow_enabled,
+  DROP COLUMN IF EXISTS ai_backfill_cancel_requested;
+
+NOTIFY pgrst, 'reload schema';

supabase/migrations/20260504180000_invoice_inbox_remove_ai_columns.sql

@@ -0,0 +1,50 @@
+-- Strip AI/LLM artifacts from invoice_inbox_items.
+--
+-- After the AI subsystem teardown (migration 20260504120000) the inbox is
+-- restored as a deterministic ingest pipeline (pdfjs-dist + regex). Drop
+-- columns that only made sense with an AI extractor / matcher / template
+-- suggester. Tighten the status enum to received | error.
+--
+-- The extracted_data jsonb column survives — any prior parsed values from
+-- the AI flow remain readable, and the new deterministic extractor writes
+-- the same shape (InvoiceExtractionResult).
+
+-- 1. Drop AI-specific columns. Done in a single ALTER for atomicity.
+ALTER TABLE public.invoice_inbox_items
+  DROP COLUMN IF EXISTS confidence,
+  DROP COLUMN IF EXISTS raw_llm_response,
+  DROP COLUMN IF EXISTS suggested_template_id,
+  DROP COLUMN IF EXISTS suggested_template_confidence,
+  DROP COLUMN IF EXISTS match_confidence,
+  DROP COLUMN IF EXISTS match_method,
+  DROP COLUMN IF EXISTS match_reasoning,
+  DROP COLUMN IF EXISTS matched_transaction_id,
+  DROP COLUMN IF EXISTS linked_receipt_id,
+  DROP COLUMN IF EXISTS document_type;
+
+-- 2. Drop indexes that referenced the dropped columns. Postgres drops
+--    indexes automatically when the column is dropped, but we also kill
+--    composite indexes that may have used document_type.
+DROP INDEX IF EXISTS public.idx_invoice_inbox_items_match_status;
+DROP INDEX IF EXISTS public.idx_invoice_inbox_items_document_type;
+DROP INDEX IF EXISTS public.idx_inbox_items_document_type_status;
+
+-- 3. Tighten the status enum. Existing rows in the now-removed AI states
+--    collapse to 'received'; rows that successfully created a supplier
+--    invoice keep 'received' and rely on created_supplier_invoice_id IS
+--    NOT NULL to mark them as processed in the UI.
+ALTER TABLE public.invoice_inbox_items
+  DROP CONSTRAINT IF EXISTS invoice_inbox_items_status_check;
+
+UPDATE public.invoice_inbox_items
+  SET status = 'received'
+  WHERE status IN ('pending', 'processing', 'ready', 'confirmed', 'rejected');
+
+ALTER TABLE public.invoice_inbox_items
+  ADD CONSTRAINT invoice_inbox_items_status_check
+  CHECK (status IN ('received', 'error'));
+
+ALTER TABLE public.invoice_inbox_items
+  ALTER COLUMN status SET DEFAULT 'received';
+
+NOTIFY pgrst, 'reload schema';