diff --git a/db/migrations/002_partnerships.sql b/db/migrations/002_partnerships.sql
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+++ b/db/migrations/002_partnerships.sql
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+-- SeCu Partnerships (Subunternehmer-System)
+-- Version: 1.1.0
+
+-- Partnerschaften zwischen Organisationen
+CREATE TABLE IF NOT EXISTS org_partnerships (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    
+    -- Hauptunternehmer (der Aufträge vergibt)
+    contractor_org_id UUID NOT NULL REFERENCES organizations(id) ON DELETE CASCADE,
+    
+    -- Subunternehmer (der Mitarbeiter stellt)
+    subcontractor_org_id UUID NOT NULL REFERENCES organizations(id) ON DELETE CASCADE,
+    
+    -- Status der Partnerschaft
+    status VARCHAR(20) NOT NULL DEFAULT 'pending' 
+        CHECK (status IN ('pending', 'active', 'paused', 'terminated')),
+    
+    -- Vertragsdetails
+    contract_start DATE,
+    contract_end DATE,
+    notes TEXT,
+    
+    -- Wer hat eingeladen
+    invited_by UUID REFERENCES users(id),
+    accepted_by UUID REFERENCES users(id),
+    accepted_at TIMESTAMP WITH TIME ZONE,
+    
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    
+    -- Ein Subunternehmer kann nur einmal pro Hauptunternehmer existieren
+    UNIQUE(contractor_org_id, subcontractor_org_id),
+    
+    -- Keine Selbst-Partnerschaft
+    CHECK (contractor_org_id != subcontractor_org_id)
+);
+
+-- Stundensätze und Konditionen pro Partnerschaft
+CREATE TABLE IF NOT EXISTS partnership_rates (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    partnership_id UUID NOT NULL REFERENCES org_partnerships(id) ON DELETE CASCADE,
+    
+    -- Art des Satzes
+    rate_type VARCHAR(50) NOT NULL DEFAULT 'hourly',  -- hourly, daily, fixed, per_order
+    
+    -- Bezeichnung (z.B. "Normaldienst", "Nachtdienst", "Wochenende")
+    name VARCHAR(100) NOT NULL,
+    description TEXT,
+    
+    -- Betrag in Cent (für Genauigkeit)
+    amount_cents INTEGER NOT NULL,
+    currency VARCHAR(3) DEFAULT 'EUR',
+    
+    -- Gültigkeit
+    valid_from DATE DEFAULT CURRENT_DATE,
+    valid_until DATE,
+    
+    -- Standard-Satz?
+    is_default BOOLEAN DEFAULT false,
+    
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+);
+
+-- Geteilte Aufträge (Hauptunternehmer -> Subunternehmer)
+CREATE TABLE IF NOT EXISTS shared_orders (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    partnership_id UUID NOT NULL REFERENCES org_partnerships(id) ON DELETE CASCADE,
+    
+    -- Original-Auftrag beim Hauptunternehmer
+    original_order_id UUID NOT NULL REFERENCES orders(id) ON DELETE CASCADE,
+    
+    -- Kopie/Referenz beim Subunternehmer (optional, wenn sie eigene Aufträge anlegen)
+    sub_order_id UUID REFERENCES orders(id) ON DELETE SET NULL,
+    
+    -- Welcher Satz gilt für diesen Auftrag
+    rate_id UUID REFERENCES partnership_rates(id),
+    
+    -- Anzahl benötigter Mitarbeiter vom Subunternehmer
+    required_staff INTEGER DEFAULT 1,
+    
+    -- Status
+    status VARCHAR(20) NOT NULL DEFAULT 'requested'
+        CHECK (status IN ('requested', 'accepted', 'declined', 'completed', 'cancelled')),
+    
+    -- Notizen zwischen den Unternehmen
+    contractor_notes TEXT,
+    subcontractor_notes TEXT,
+    
+    responded_at TIMESTAMP WITH TIME ZONE,
+    completed_at TIMESTAMP WITH TIME ZONE,
+    
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+);
+
+-- Stundenzettel von Subunternehmer-Mitarbeitern für geteilte Aufträge
+CREATE TABLE IF NOT EXISTS partnership_timesheets (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    shared_order_id UUID NOT NULL REFERENCES shared_orders(id) ON DELETE CASCADE,
+    
+    -- Original-Stundenzettel beim Subunternehmer
+    timesheet_id UUID NOT NULL REFERENCES timesheets(id) ON DELETE CASCADE,
+    
+    -- Welcher Satz wurde angewendet
+    rate_id UUID REFERENCES partnership_rates(id),
+    
+    -- Berechneter Betrag
+    calculated_amount_cents INTEGER,
+    
+    -- Status der Freigabe durch Hauptunternehmer
+    approval_status VARCHAR(20) DEFAULT 'pending'
+        CHECK (approval_status IN ('pending', 'approved', 'disputed', 'rejected')),
+    
+    approved_by UUID REFERENCES users(id),
+    approved_at TIMESTAMP WITH TIME ZONE,
+    dispute_reason TEXT,
+    
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+);
+
+-- Abrechnungen zwischen Partnern
+CREATE TABLE IF NOT EXISTS partnership_invoices (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    partnership_id UUID NOT NULL REFERENCES org_partnerships(id) ON DELETE CASCADE,
+    
+    -- Rechnungsnummer
+    invoice_number VARCHAR(50) NOT NULL,
+    
+    -- Abrechnungszeitraum
+    period_start DATE NOT NULL,
+    period_end DATE NOT NULL,
+    
+    -- Beträge
+    subtotal_cents INTEGER NOT NULL DEFAULT 0,
+    tax_percent DECIMAL(5,2) DEFAULT 19.00,
+    tax_cents INTEGER NOT NULL DEFAULT 0,
+    total_cents INTEGER NOT NULL DEFAULT 0,
+    
+    -- Status
+    status VARCHAR(20) NOT NULL DEFAULT 'draft'
+        CHECK (status IN ('draft', 'sent', 'paid', 'overdue', 'cancelled')),
+    
+    -- Daten
+    issued_at TIMESTAMP WITH TIME ZONE,
+    due_date DATE,
+    paid_at TIMESTAMP WITH TIME ZONE,
+    
+    -- PDF-Link (wenn generiert)
+    pdf_url TEXT,
+    
+    -- Notizen
+    notes TEXT,
+    
+    created_by UUID REFERENCES users(id),
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+);
+
+-- Rechnungspositionen
+CREATE TABLE IF NOT EXISTS partnership_invoice_items (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+    invoice_id UUID NOT NULL REFERENCES partnership_invoices(id) ON DELETE CASCADE,
+    
+    -- Referenz zum Stundenzettel (optional)
+    partnership_timesheet_id UUID REFERENCES partnership_timesheets(id),
+    
+    -- Beschreibung
+    description TEXT NOT NULL,
+    
+    -- Mengen und Preise
+    quantity DECIMAL(10,2) NOT NULL DEFAULT 1,
+    unit VARCHAR(20) DEFAULT 'Stunden',
+    unit_price_cents INTEGER NOT NULL,
+    total_cents INTEGER NOT NULL,
+    
+    -- Datum der Leistung
+    service_date DATE,
+    
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
+);
+
+-- Indexes
+CREATE INDEX IF NOT EXISTS idx_partnerships_contractor ON org_partnerships(contractor_org_id);
+CREATE INDEX IF NOT EXISTS idx_partnerships_subcontractor ON org_partnerships(subcontractor_org_id);
+CREATE INDEX IF NOT EXISTS idx_partnerships_status ON org_partnerships(status);
+CREATE INDEX IF NOT EXISTS idx_shared_orders_partnership ON shared_orders(partnership_id);
+CREATE INDEX IF NOT EXISTS idx_shared_orders_original ON shared_orders(original_order_id);
+CREATE INDEX IF NOT EXISTS idx_partnership_timesheets_shared ON partnership_timesheets(shared_order_id);
+CREATE INDEX IF NOT EXISTS idx_partnership_invoices_partnership ON partnership_invoices(partnership_id);
+CREATE INDEX IF NOT EXISTS idx_partnership_invoices_status ON partnership_invoices(status);
+
+-- Partnership-Modul registrieren
+INSERT INTO modules (name, display_name, description, is_core, default_config) VALUES
+    ('partnerships', 'Subunternehmer', 'Zusammenarbeit mit Subunternehmen inkl. Abrechnung', false, 
+     '{"auto_approve_timesheets": false, "default_payment_days": 30}')
+ON CONFLICT (name) DO NOTHING;