get_resource/get_requirement_options: #[server(default)] on params

An empty params map serializes to no `params` key at all on a real
client-side call, so every Resource::refetch() after an empty-params
fetch failed with "missing field params" - only ever masked before
because a resource's *first* load is always server-resolved during
SSR, never round-tripping through serialization at all. Surfaced by
the new shared batch-confirm button's post-confirm refetch, but this
already affected the old per-row confirm's refetch identically -
pre-existing, not new.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/resource.rs

@@ -21,6 +21,13 @@ pub async fn get_resource(
     question_id: String,
     alternative: String,
     feature_name: String,
+    // An empty map serializes as no `params` key at all on a real
+    // client-side call (unlike the server-only initial SSR call, which
+    // never round-trips through serialization) - without this, every
+    // `Resource::refetch()` after a fully-empty-params call failed with
+    // "missing field `params`", even though the very first load (always
+    // server-resolved) never did.
+    #[server(default)]
     params: std::collections::HashMap<String, String>,
 ) -> Result<serde_json::Value, ServerFnError> {
     use crate::server::AppState;
@@ -48,6 +55,8 @@ pub async fn get_requirement_options(
     alternative: String,
     feature_name: String,
     requirement_name: String,
+    // See get_resource's `params` for why this is needed.
+    #[server(default)]
     params: std::collections::HashMap<String, String>,
 ) -> Result<serde_json::Value, ServerFnError> {
     use crate::server::AppState;