Default cookie consent to GDPR and track its source

When IP geolocation does not resolve a country, or resolves one with no
known cookie-consent regulation (common on localhost and unmapped
regions), the banner previously fell back to OPT_OUT with no recorded
regulation. Apply GDPR (OPT_IN) as the safe default in that case so the
strictest consent model wins when origin is unknown.

To keep consent records auditable, stamp each one with a regulation
source of DETECTED (resolved from geolocation) or DEFAULT (fell back to
GDPR). The shared cookiebanner.ResolveRegulation helper centralizes the
decision for both the config and consent endpoints, and the new value is
exposed through GraphQL, MCP, the CLI, the n8n node, and the console
consent-records views.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/server/api/mcp/v1/specification.yaml

@@ -216,6 +216,13 @@ components:
         - PDPL
       go.probo.inc/mcpgen/type: go.probo.inc/probo/pkg/coredata.Regulation
 
+    RegulationSource:
+      type: string
+      enum:
+        - DETECTED
+        - DEFAULT
+      go.probo.inc/mcpgen/type: go.probo.inc/probo/pkg/coredata.RegulationSource
+
     CountryCode:
       type: string
       enum:
@@ -9715,6 +9722,10 @@ components:
           $ref: "#/components/schemas/Regulation"
           description: Applicable regulation
           nullable: true
+        regulation_source:
+          $ref: "#/components/schemas/RegulationSource"
+          description: Whether the regulation was detected from geolocation or defaulted to GDPR
+          nullable: true
         country_code:
           $ref: "#/components/schemas/CountryCode"
           description: Visitor country code (ISO 3166-1 alpha-2)