Fix/supp ag fb (#1023)

* fix: prevent credit notes from entering payment flow

* fix: persist and display customer personal numbers

* feat: configure automatic invoice reminder days

* fix: issue credit notes through send flow

* chore: add repository agent guidance

* feat(mcp): route tools across user companies

* fix(articles): delete unused register entries

* feat(invoices): improve issued invoice actions

* feat(supplier-invoices): retain uploaded source documents

* docs: record implementation decisions

* feat: enhance customer personal number handling and validation

- Updated CustomerForm to allow personal numbers in the format of "********-1234" for individual customers.
- Added validation to ensure personal numbers are only accepted for individual customers in CreateCustomerSchema.
- Implemented masking and encryption for personal numbers to enhance data protection.
- Introduced new utility functions for masking and encrypting personal numbers.
- Added database migration to enforce unique constraints on credit note relationships and prevent duplicate entries.
- Enhanced error handling and logging for credit note issuance and invoice processing.
- Updated tests to cover new credit note creation guards and personal number handling.

* test: enhance list companies test with supabase query mocks

lib/email/reminder-templates.ts

@@ -355,10 +355,34 @@ export function generateReminderEmailSubject(data: ReminderEmailData): string {
 /**
  * Get the number of days after due date for each reminder level
  */
-export function getReminderDaysConfig(): Record<1 | 2 | 3, number> {
-  return {
+export type ReminderDaysConfig = Record<1 | 2 | 3, number>
+
+type ReminderDaysSettings = Partial<
+  Pick<
+    CompanySettings,
+    'reminder_days_level_1' | 'reminder_days_level_2' | 'reminder_days_level_3'
+  >
+>
+
+export function getReminderDaysConfig(
+  settings?: ReminderDaysSettings | null,
+): ReminderDaysConfig {
+  const defaults: ReminderDaysConfig = {
     1: REMINDER_CONFIG[1].daysAfterDue,
     2: REMINDER_CONFIG[2].daysAfterDue,
-    3: REMINDER_CONFIG[3].daysAfterDue
+    3: REMINDER_CONFIG[3].daysAfterDue,
   }
+
+  const configured: ReminderDaysConfig = {
+    1: settings?.reminder_days_level_1 ?? defaults[1],
+    2: settings?.reminder_days_level_2 ?? defaults[2],
+    3: settings?.reminder_days_level_3 ?? defaults[3],
+  }
+
+  const valid =
+    Object.values(configured).every((days) => Number.isInteger(days) && days >= 1 && days <= 365)
+    && configured[1] < configured[2]
+    && configured[2] < configured[3]
+
+  return valid ? configured : defaults
 }