Phase 0 Complete: Tasks 0.7-0.20

- 0.7: UI-Design-Richtlinien (docs/ui-design-guidelines.md, 535 lines)
- 0.8: Theme-Customization Backend (4 theme fields, migration 0023)
- 0.9: Theme-Customization Frontend (SettingsTheme.tsx, themeStore.ts, live preview)
- 0.10: RBAC-Audit (4 plugins secured, 53 routes with require_permission)
- 0.11: LiteLLM-Cleanup (llm_client.py migrated from httpx to litellm)
- 0.12: KI-Agent-Framework docs (plugin-development-guide.md, agent_capabilities field)
- 0.13: Heartbeat configurable (ProactiveSettings, migration 0024, frontend UI)
- 0.14: Unified Search Field-Level RBAC (resolve_permissions + filter_fields_by_permission)
- 0.15: Undo/History-System (EntityHistory model, service, routes, migration 0025, HistoryViewer)
- 0.16: Storage Backend (LocalStorage + S3Storage, DMS/attachments/mail updated)
- 0.17: Import/Export unified Contact fields (firstname, surname, email_1, phone_1)
- 0.18: .gitignore & Config-Cleanup (webui→frontend, python-jose removed, .env untracked)
- 0.19: Mail-Salt Security-Fix (per-account random salt, migration 0026)
- 0.20: AGPL replaced (PyMuPDF→pypdf, OnlyOffice→Collabora, LICENSE + THIRD_PARTY_LICENSES.md)

app/services/system_settings_service.py

@@ -34,6 +34,10 @@ def _settings_to_dict(s: SystemSettings) -> dict[str, Any]:
         "invoice_prefix": s.invoice_prefix,
         "quote_prefix": s.quote_prefix,
         "payment_terms_days": s.payment_terms_days,
+        "theme_primary_color": s.theme_primary_color,
+        "theme_accent_color": s.theme_accent_color,
+        "theme_font_family": s.theme_font_family,
+        "theme_border_radius": s.theme_border_radius,
         "created_at": s.created_at.isoformat() if s.created_at else None,
         "updated_at": s.updated_at.isoformat() if s.updated_at else None,
     }
@@ -106,6 +110,10 @@ async def upsert_system_settings(
             invoice_prefix=data.get("invoice_prefix", "RE-"),
             quote_prefix=data.get("quote_prefix", "AN-"),
             payment_terms_days=data.get("payment_terms_days", 14),
+            theme_primary_color=data.get("theme_primary_color", "#2563eb"),
+            theme_accent_color=data.get("theme_accent_color", "#d946ef"),
+            theme_font_family=data.get("theme_font_family", "Inter"),
+            theme_border_radius=data.get("theme_border_radius", "0.5rem"),
         )
         db.add(settings)
         await db.flush()
@@ -122,6 +130,7 @@ async def upsert_system_settings(
             "company_zip", "company_country", "tax_number", "vat_id", "iban",
             "bic", "bank_name", "ceo", "trade_register",
             "invoice_prefix", "quote_prefix", "payment_terms_days",
+            "theme_primary_color", "theme_accent_color", "theme_font_family", "theme_border_radius",
         )
         for field in all_fields:
             if field in data and data[field] is not None: