fix: default page param to 1 in funnel step sessions and goal sessions (#940)

When the `page` query parameter is omitted, the offset calculation
`(page - 1) * (limit || 25)` produces NaN, which causes the ClickHouse
query to fail with a 500 error.

Default `page` to 1 so both endpoints work without an explicit page param,
matching the behavior of other paginated endpoints like getSessions.

Fixes #939

Author: Tchoow

server/src/api/analytics/funnels/getFunnelStepSessions.ts

@@ -259,7 +259,7 @@ export async function getFunnelStepSessions(req: FastifyRequest<GetFunnelStepSes
       query_params: {
         siteId: Number(siteId),
         limit: limit || 25,
-        offset: (page - 1) * (limit || 25),
+        offset: ((page || 1) - 1) * (limit || 25),
       },
     });
 

server/src/api/analytics/goals/getGoalSessions.ts

@@ -166,7 +166,7 @@ export async function getGoalSessions(req: FastifyRequest<GetGoalSessionsRequest
       query_params: {
         siteId: Number(siteId),
         limit: limit || 25,
-        offset: (page - 1) * (limit || 25),
+        offset: ((page || 1) - 1) * (limit || 25),
       },
     });