feat: multi-tenant company refactor (GNU-19) (#153)

* feat: multi-tenant company refactor (GNU-19)

Introduce companies table, company_members, and user_preferences to
support multiple companies per user. All data scoping changes from
user_id to company_id across the entire codebase.

Key changes:
- Database migration: new tables, company_id on 40+ tables, backfill,
  RLS rewrite from user_id to company-member-based, updated RPCs
- Types: Company, CompanyMember, CompanyRole, UserPreferences types;
  company_id added to all entity interfaces; companyId on all events
- Engine: all 7 core functions take companyId; storno, period, year-end
  services updated; 16 report generators updated
- Middleware: company context resolution (cookie → prefs → first company)
- API routes: ~120 routes updated with requireCompanyId()
- Frontend: CompanyProvider context, layout/dashboard/onboarding updated
- Extensions: context factory, 9 extensions, all lib files updated
- Tests: 1880 tests passing, all helpers updated with company_id defaults

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add database migrations for multi-tenant company and team system (GNU-19)

Adds company_invitations, company creation RPC, team_members, account
deletion RPC, and teams table refactor migrations. Updates base
multi-tenant migration with cascading FKs and onboarding_step column.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add team types and update core infrastructure for multi-tenancy (GNU-19)

Adds TeamRole, MemberSource, and Team types. Refactors Supabase service
client to be stateless, updates middleware for team-aware routing, extends
CompanyContext with team/role fields, and updates extension service types
to accept companyId.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor: thread company_id through business logic functions (GNU-19)

Replaces user_id scoping with company_id across all lib modules:
bookkeeping, documents, transactions, invoices, reconciliation, tax,
deadlines, and import. Updates corresponding tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor: thread company_id through API routes and extensions (GNU-19)

Updates all existing API routes to extract and pass companyId. Updates
enable-banking and arcim-migration extensions for company-scoped
transaction ingestion and sync.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add company and team management API routes (GNU-19)

Adds CRUD endpoints for company members, company invitations, team
members, and team invitations. Includes invite token utilities, email
templates, and company switch server action.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add team/company UI components, pages, and dashboard updates (GNU-19)

Adds CompanySwitcher, ConsultantEmptyState, Step0RoleChoice, company
members and team management panels. Updates dashboard layout for
team-aware routing, onboarding for multi-step role choice, and auth
callback for team invite acceptance. Ignores supabase/.branches/.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: add null guards for company in import page (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: move appUrl declaration to outer scope in invite route (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: add optional chaining for company.name in members section (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: add optional chaining for second company.name in members section (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: add null guards for company in extension components (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: pass companyId to executeSIEImport in arcim-migration extension (GNU-19)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update tests to use companyId instead of userId and improve type handling

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/api/reconciliation/bank/link/route.ts

@@ -4,6 +4,7 @@ import { ensureInitialized } from '@/lib/init'
 import { manualLink } from '@/lib/reconciliation/bank-reconciliation'
 import { validateBody } from '@/lib/api/validate'
 import { BankLinkSchema } from '@/lib/api/schemas'
+import { requireCompanyId } from '@/lib/company/context'
 
 ensureInitialized()
 
@@ -15,11 +16,13 @@ export async function POST(request: Request) {
     return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   }
 
+  const companyId = await requireCompanyId(supabase, user.id)
+
   const validation = await validateBody(request, BankLinkSchema)
   if (!validation.success) return validation.response
   const { transaction_id, journal_entry_id } = validation.data
 
-  const result = await manualLink(supabase, user.id, transaction_id, journal_entry_id)
+  const result = await manualLink(supabase, companyId, transaction_id, journal_entry_id)
 
   if (!result.success) {
     return NextResponse.json({ error: result.error }, { status: 400 })

app/api/reconciliation/bank/run/route.ts

@@ -4,6 +4,7 @@ import { ensureInitialized } from '@/lib/init'
 import { runReconciliation } from '@/lib/reconciliation/bank-reconciliation'
 import { validateBody } from '@/lib/api/validate'
 import { RunReconciliationSchema } from '@/lib/api/schemas'
+import { requireCompanyId } from '@/lib/company/context'
 
 ensureInitialized()
 
@@ -15,11 +16,13 @@ export async function POST(request: Request) {
     return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   }
 
+  const companyId = await requireCompanyId(supabase, user.id)
+
   const validation = await validateBody(request, RunReconciliationSchema)
   if (!validation.success) return validation.response
   const { date_from, date_to, dry_run } = validation.data
 
-  const result = await runReconciliation(supabase, user.id, {
+  const result = await runReconciliation(supabase, companyId, {
     dateFrom: date_from,
     dateTo: date_to,
     dryRun: dry_run ?? false,

app/api/reconciliation/bank/status/route.ts

@@ -1,6 +1,7 @@
 import { createClient } from '@/lib/supabase/server'
 import { NextResponse } from 'next/server'
 import { getReconciliationStatus } from '@/lib/reconciliation/bank-reconciliation'
+import { requireCompanyId } from '@/lib/company/context'
 
 export async function GET(request: Request) {
   const supabase = await createClient()
@@ -10,11 +11,13 @@ export async function GET(request: Request) {
     return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   }
 
+  const companyId = await requireCompanyId(supabase, user.id)
+
   const { searchParams } = new URL(request.url)
   const dateFrom = searchParams.get('date_from') || undefined
   const dateTo = searchParams.get('date_to') || undefined
 
-  const status = await getReconciliationStatus(supabase, user.id, dateFrom, dateTo)
+  const status = await getReconciliationStatus(supabase, companyId, dateFrom, dateTo)
 
   return NextResponse.json({ data: status })
 }

app/api/reconciliation/bank/unlink/route.ts

@@ -3,6 +3,7 @@ import { NextResponse } from 'next/server'
 import { unlinkReconciliation } from '@/lib/reconciliation/bank-reconciliation'
 import { validateBody } from '@/lib/api/validate'
 import { BankUnlinkSchema } from '@/lib/api/schemas'
+import { requireCompanyId } from '@/lib/company/context'
 
 export async function POST(request: Request) {
   const supabase = await createClient()
@@ -12,11 +13,13 @@ export async function POST(request: Request) {
     return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   }
 
+  const companyId = await requireCompanyId(supabase, user.id)
+
   const validation = await validateBody(request, BankUnlinkSchema)
   if (!validation.success) return validation.response
   const { transaction_id } = validation.data
 
-  const result = await unlinkReconciliation(supabase, user.id, transaction_id)
+  const result = await unlinkReconciliation(supabase, companyId, transaction_id)
 
   if (!result.success) {
     return NextResponse.json({ error: result.error }, { status: 400 })

app/api/reconciliation/bank/unmatched-entries/route.ts

@@ -1,6 +1,7 @@
 import { createClient } from '@/lib/supabase/server'
 import { NextResponse } from 'next/server'
 import { fetchUnlinkedGLLines } from '@/lib/reconciliation/bank-reconciliation'
+import { requireCompanyId } from '@/lib/company/context'
 
 export async function GET(request: Request) {
   const supabase = await createClient()
@@ -10,11 +11,13 @@ export async function GET(request: Request) {
     return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
   }
 
+  const companyId = await requireCompanyId(supabase, user.id)
+
   const { searchParams } = new URL(request.url)
   const dateFrom = searchParams.get('date_from') || undefined
   const dateTo = searchParams.get('date_to') || undefined
 
-  const lines = await fetchUnlinkedGLLines(supabase, user.id, dateFrom, dateTo)
+  const lines = await fetchUnlinkedGLLines(supabase, companyId, dateFrom, dateTo)
 
   return NextResponse.json({ data: lines })
 }