feat(cmp): vendor-agnostic consent data model — 13 new fields

Extend banner consent records with consent_method, banner_version,
banner_config_hash, geo, page_url, referrer, device info, session_id
and consent_scope for full Art. 7 DSGVO proof with any tracking vendor.

Migration 107, backward-compatible (all fields nullable).
Admin detail modal shows tracking context, device info and technical data.
Fix pre-existing str|None → Optional[str] for Python 3.9 compat.

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

backend-compliance/migrations/107_banner_vendor_agnostic.sql

@@ -0,0 +1,69 @@
+-- Migration 107: Vendor-agnostische Felder fuer Banner-Consents
+-- Erweitert compliance_banner_consents um Felder die fuer beliebige
+-- Tracking-Anbieter (GA4, Matomo, HubSpot etc.) benoetigt werden.
+-- Alle Felder nullable → backward-compatible.
+
+-- Consent-Methode: wie hat der User entschieden
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS consent_method TEXT;
+    -- "accept_all" / "reject_all" / "custom_selection"
+
+-- Banner-Version + Config-Hash zum Zeitpunkt des Consents (Art. 7(1) DSGVO)
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS banner_version INTEGER;
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS banner_config_hash TEXT;
+
+-- Geo-Daten fuer EWR-Only-Logik
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS geo_country TEXT;
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS geo_region TEXT;
+
+-- Geltungsbereich: "page" / "domain" / "cross-domain"
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS consent_scope TEXT DEFAULT 'domain';
+
+-- Tracking-Kontext
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS page_url TEXT;
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS referrer TEXT;
+
+-- Device-Informationen (parsed aus User-Agent im Frontend)
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS device_type TEXT;
+    -- "mobile" / "desktop" / "tablet"
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS browser TEXT;
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS os TEXT;
+
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS screen_resolution TEXT;
+
+-- Session-basierte Zuordnung
+ALTER TABLE compliance_banner_consents
+    ADD COLUMN IF NOT EXISTS session_id TEXT;
+
+-- Audit-Log ebenfalls erweitern (consent_method fuer Nachweis)
+ALTER TABLE compliance_banner_consent_audit_log
+    ADD COLUMN IF NOT EXISTS consent_method TEXT;
+
+ALTER TABLE compliance_banner_consent_audit_log
+    ADD COLUMN IF NOT EXISTS page_url TEXT;
+
+-- Index auf consent_method fuer Reporting
+CREATE INDEX IF NOT EXISTS idx_banner_consent_method
+    ON compliance_banner_consents (consent_method)
+    WHERE consent_method IS NOT NULL;
+
+-- Index auf session_id fuer Session-Lookup
+CREATE INDEX IF NOT EXISTS idx_banner_consent_session
+    ON compliance_banner_consents (session_id)
+    WHERE session_id IS NOT NULL;