feat: Obligations-Modul auf 100% — vollständige CRUD-Implementierung

- Backend: compliance_obligations Tabelle (Migration 013)
- Backend: obligation_routes.py — GET/POST/PUT/DELETE + Stats-Endpoint
- Backend: obligation_router in __init__.py registriert
- Frontend: obligations/page.tsx — ObligationModal, ObligationDetail, ObligationCard, alle Buttons verdrahtet
- Proxy: PATCH-Methode in compliance catch-all route ergänzt
- Tests: 39/39 Obligation-Tests (Schemas, Helpers, Business Logic)

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

backend-compliance/migrations/013_obligations.sql

@@ -0,0 +1,31 @@
+-- Migration 013: Compliance Obligations Tracking
+-- Standalone obligation items (DSGVO/AI-Act Pflichten-Verwaltung)
+-- Derived from UCCA assessments or created manually
+
+SET search_path TO compliance, core, public;
+
+CREATE TABLE IF NOT EXISTS compliance_obligations (
+    id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    tenant_id       UUID NOT NULL DEFAULT '9282a473-5c95-4b3a-bf78-0ecc0ec71d3e',
+    title           TEXT NOT NULL,
+    description     TEXT,
+    source          TEXT NOT NULL DEFAULT 'DSGVO',   -- 'DSGVO', 'AI Act', 'NIS2', etc.
+    source_article  TEXT,                            -- e.g. 'Art. 35', 'Art. 9'
+    deadline        TIMESTAMPTZ,
+    status          TEXT NOT NULL DEFAULT 'pending', -- pending|in-progress|completed|overdue
+    priority        TEXT NOT NULL DEFAULT 'medium',  -- critical|high|medium|low
+    responsible     TEXT,
+    linked_systems  JSONB DEFAULT '[]'::jsonb,
+    -- Link to UCCA assessment (if auto-derived)
+    assessment_id   UUID,
+    rule_code       TEXT,                            -- UCCA rule code if derived
+    notes           TEXT,
+    created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_obligations_tenant    ON compliance_obligations(tenant_id);
+CREATE INDEX IF NOT EXISTS idx_obligations_status    ON compliance_obligations(status);
+CREATE INDEX IF NOT EXISTS idx_obligations_priority  ON compliance_obligations(priority);
+CREATE INDEX IF NOT EXISTS idx_obligations_deadline  ON compliance_obligations(deadline) WHERE deadline IS NOT NULL;
+CREATE INDEX IF NOT EXISTS idx_obligations_created   ON compliance_obligations(created_at DESC);