Generate tracker policy document from banner snapshot

Add a markdown "Cookie and Tracking Technologies Policy" template in
the policy-writer tone that covers cookies and other tracking
technologies, with GDPR, UK GDPR, FADP, and CCPA/CPRA privacy-rights
framing. Convert it to ProseMirror JSON and add PublishTrackerPolicy,
which builds the document from a banner's latest published version
snapshot and its tracker third parties. The document is GENERATED and
private in the trust center, linked to the banner via
policy_document_id.

Add CookieItem.HumanizedDuration so server-rendered lifetimes match the
banner's humanizeDuration helper, and reword the publish trigger and
backfill comment to reflect the broader tracker scope.

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

pkg/cookiebanner/service.go

@@ -966,7 +966,7 @@ func (s *Service) PublishCookieBannerVersion(
 
 			banner := coredata.CookieBanner{ID: bannerID}
 			if err := banner.SetPolicyGenerationRequested(ctx, tx); err != nil {
-				return fmt.Errorf("cannot request cookie policy generation: %w", err)
+				return fmt.Errorf("cannot request tracker policy generation: %w", err)
 			}
 
 			return nil