fix: resolve merge conflicts from P0 role-based + audit trail branches

Combine role-based permissions (VerifyAccess/GetUserRole) with audit trail
(IP/user-agent context capture) in auth middleware and tenant resolver.

backend/internal/auth/tenant_resolver.go

@@ -12,12 +12,8 @@ import (
 // Defined as an interface to avoid circular dependency with services.
 type TenantLookup interface {
 	FirstTenantForUser(ctx context.Context, userID uuid.UUID) (*uuid.UUID, error)
-<<<<<<< HEAD
 	VerifyAccess(ctx context.Context, userID, tenantID uuid.UUID) (bool, error)
-||||||| 82878df
-=======
 	GetUserRole(ctx context.Context, userID, tenantID uuid.UUID) (string, error)
->>>>>>> mai/pike/p0-role-based
 }
 
 // TenantResolver is middleware that resolves the tenant from X-Tenant-ID header
@@ -46,35 +42,20 @@ func (tr *TenantResolver) Resolve(next http.Handler) http.Handler {
 				http.Error(w, `{"error":"invalid X-Tenant-ID"}`, http.StatusBadRequest)
 				return
 			}
-<<<<<<< HEAD
 
-			// Verify user has access to this tenant
-			hasAccess, err := tr.lookup.VerifyAccess(r.Context(), userID, parsed)
+			// Verify user has access and get their role
+			role, err := tr.lookup.GetUserRole(r.Context(), userID, parsed)
 			if err != nil {
 				slog.Error("tenant access check failed", "error", err, "user_id", userID, "tenant_id", parsed)
 				http.Error(w, `{"error":"internal error"}`, http.StatusInternalServerError)
 				return
 			}
-			if !hasAccess {
+			if role == "" {
 				http.Error(w, `{"error":"no access to tenant"}`, http.StatusForbidden)
 				return
 			}
 
-||||||| 82878df
-=======
-			// Verify user has access and get their role
-			role, err := tr.lookup.GetUserRole(r.Context(), userID, parsed)
-			if err != nil {
-				http.Error(w, "error checking tenant access", http.StatusInternalServerError)
-				return
-			}
-			if role == "" {
-				http.Error(w, "no access to this tenant", http.StatusForbidden)
-				return
-			}
->>>>>>> mai/pike/p0-role-based
 			tenantID = parsed
-			// Override the role from middleware with the correct one for this tenant
 			r = r.WithContext(ContextWithUserRole(r.Context(), role))
 		} else {
 			// Default to user's first tenant (role already set by middleware)