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/compliance/db/banner_models.py

@@ -35,6 +35,20 @@ class BannerConsentDB(Base):
     user_agent = Column(Text)
     consent_string = Column(Text)
     linked_email = Column(Text)
+    # Vendor-agnostische Felder (Migration 107)
+    consent_method = Column(Text)          # accept_all / reject_all / custom_selection
+    banner_version = Column(Integer)
+    banner_config_hash = Column(Text)
+    geo_country = Column(Text)
+    geo_region = Column(Text)
+    consent_scope = Column(Text, default='domain')
+    page_url = Column(Text)
+    referrer = Column(Text)
+    device_type = Column(Text)             # mobile / desktop / tablet
+    browser = Column(Text)
+    os = Column(Text)
+    screen_resolution = Column(Text)
+    session_id = Column(Text)
     expires_at = Column(DateTime)
     created_at = Column(DateTime, nullable=False, default=datetime.utcnow)
     updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
@@ -63,6 +77,8 @@ class BannerConsentAuditLogDB(Base):
     ip_hash = Column(Text)
     banner_config_hash = Column(Text)
     consent_version = Column(Integer)
+    consent_method = Column(Text)
+    page_url = Column(Text)
     created_at = Column(DateTime, nullable=False, default=datetime.utcnow)
 
     __table_args__ = (