Refactor to generic ERP base

Remove influencer-specific features (campaigns, TikTok, gifts, shadow ledger,
contracts, briefings) and consolidate into a clean ERP foundation with core
bookkeeping, invoicing, receipts, tax reporting, and calendar functionality.
Reorganize database migrations into a clean numbered sequence.

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

lib/tax/deadline-config.ts

@@ -1,6 +1,6 @@
 /**
  * Static configuration of all Swedish tax deadlines (Skatteverket)
- * Based on dev_docs/influencer_ai_info/07-kalender-deadlines.md
+ * Based on Skatteverket's official deadline schedule
  */
 
 import type { TaxDeadlineType, EntityType, MomsPeriod } from '@/types'

lib/tax/expense-warnings.ts

@@ -141,8 +141,6 @@ export function getCategoryDisplayName(category: string): string {
   const names: Record<string, string> = {
     income_services: 'Tjänster',
     income_products: 'Produkter',
-    income_sponsorship: 'Sponsring',
-    income_affiliate: 'Affiliate',
     income_other: 'Övriga intäkter',
     expense_equipment: 'Utrustning',
     expense_software: 'Programvara',

lib/tax/light-calculator.ts

@@ -1,145 +0,0 @@
-/**
- * Light Mode Tax Calculator
- *
- * For influencers working through umbrella companies (egenanställningsföretag).
- * They don't pay egenavgifter (the umbrella handles arbetsgivaravgifter).
- * Tax exposure comes from:
- * - Gifts/PR products → personal income tax liability (municipal + church)
- * - Hobby income → egenavgifter + municipal tax on surplus (out of MVP scope)
- */
-
-import type { LightTaxEstimate } from '@/types'
-
-/**
- * Calculate light mode tax liability from gifts
- * NO egenavgifter (umbrella pays arbetsgivaravgifter)
- * NO VAT (umbrella handles)
- * NO grundavdrag (consumed by umbrella salary)
- */
-export function calculateLightTax(params: {
-  taxableGiftValue: number
-  municipalTaxRate: number // e.g. 0.3238 (32.38%)
-  churchTaxRate: number    // e.g. 0.0100 (1.00%), 0 if not member
-  hobbyIncome?: number
-  hobbyExpenses?: number
-  bankBalance: number | null
-}): LightTaxEstimate {
-  const {
-    taxableGiftValue,
-    municipalTaxRate,
-    churchTaxRate,
-    hobbyIncome = 0,
-    hobbyExpenses = 0,
-    bankBalance,
-  } = params
-
-  // Gift tax = taxable gift value × (municipal rate + church rate)
-  const effectiveRate = municipalTaxRate + churchTaxRate
-  const giftTax = Math.round(taxableGiftValue * effectiveRate)
-
-  // Hobby tax (simplified: surplus × egenavgifter + municipal tax)
-  const hobbySurplus = Math.max(0, hobbyIncome - hobbyExpenses)
-  const hobbyTax = hobbySurplus > 0
-    ? Math.round(hobbySurplus * 0.2897 + hobbySurplus * (1 - 0.2897) * municipalTaxRate)
-    : 0
-
-  const totalVirtualDebt = giftTax + hobbyTax
-  const balance = bankBalance ?? 0
-  const safeToSpend = Math.max(0, balance - totalVirtualDebt)
-  const safeToSpendPercent = balance > 0 ? (safeToSpend / balance) * 100 : 0
-
-  let safeToSpendLevel: 'green' | 'yellow' | 'red'
-  if (safeToSpendPercent > 70) {
-    safeToSpendLevel = 'green'
-  } else if (safeToSpendPercent > 30) {
-    safeToSpendLevel = 'yellow'
-  } else {
-    safeToSpendLevel = 'red'
-  }
-
-  return {
-    taxable_gift_value: taxableGiftValue,
-    municipal_tax_rate: municipalTaxRate,
-    church_tax_rate: churchTaxRate,
-    gift_tax: giftTax,
-    hobby_tax: hobbyTax,
-    total_virtual_debt: totalVirtualDebt,
-    safe_to_spend: safeToSpend,
-    safe_to_spend_percent: Math.round(safeToSpendPercent),
-    safe_to_spend_level: safeToSpendLevel,
-  }
-}
-
-/**
- * Calculate safe-to-spend from bank balance and tax estimate
- */
-export function calculateLightSafeToSpend(
-  bankBalance: number | null,
-  lightTax: LightTaxEstimate
-): { safeToSpend: number; percent: number; level: 'green' | 'yellow' | 'red' } {
-  return {
-    safeToSpend: lightTax.safe_to_spend,
-    percent: lightTax.safe_to_spend_percent,
-    level: lightTax.safe_to_spend_level,
-  }
-}
-
-/**
- * Calculate net payout from gross using umbrella provider fee structure
- * Used in shadow ledger form for auto-calculating fields
- */
-export function calculatePayoutNet(params: {
-  gross: number
-  feePercent: number       // e.g. 6.0
-  pensionPercent: number   // e.g. 4.5
-  estimatedTaxRate: number // e.g. 0.30
-}): {
-  serviceFee: number
-  pensionDeduction: number
-  socialFees: number
-  incomeTaxWithheld: number
-  net: number
-} {
-  const { gross, feePercent, pensionPercent, estimatedTaxRate } = params
-
-  // Service fee (umbrella company fee)
-  const serviceFee = Math.round(gross * (feePercent / 100) * 100) / 100
-
-  // After fee
-  const afterFee = gross - serviceFee
-
-  // Pension deduction (from remaining)
-  const pensionDeduction = Math.round(afterFee * (pensionPercent / 100) * 100) / 100
-
-  // Social fees (arbetsgivaravgifter ~31.42% paid by umbrella, deducted from gross)
-  const socialFees = Math.round(afterFee * 0.3142 * 100) / 100
-
-  // Taxable base after social fees
-  const taxableBase = afterFee - socialFees - pensionDeduction
-
-  // Preliminary income tax
-  const incomeTaxWithheld = Math.round(taxableBase * estimatedTaxRate * 100) / 100
-
-  // Net payout
-  const net = Math.round((taxableBase - incomeTaxWithheld) * 100) / 100
-
-  return {
-    serviceFee,
-    pensionDeduction,
-    socialFees,
-    incomeTaxWithheld,
-    net: Math.max(0, net),
-  }
-}
-
-/**
- * Calculate virtual tax debt for a gift (light mode)
- * Simple: gift value × effective tax rate
- */
-export function calculateGiftVirtualTaxDebt(
-  giftMarketValue: number,
-  municipalTaxRate: number,
-  churchTaxRate: number
-): number {
-  return Math.round(giftMarketValue * (municipalTaxRate + churchTaxRate))
-}