Select fields: inline static options

A select requirement can now declare a plain options: [A, B, C] list
instead of a resource - each string is both value and label. Restores
the ancestor question format's inline enums (used by the klingenberg
port) without needing a resource endpoint for a fixed list.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y42TyF8Zu7NGRR2893vNcZ

src/content.rs

@@ -446,6 +446,12 @@ pub struct Requirement {
     /// `ResourceSpec` mechanism a `Feature.resource` uses.
     #[serde(default)]
     pub resource: Option<ResourceSpec>,
+    /// `type: select` only - a static list of options, as an
+    /// alternative to a `resource`. Each string is both the option's
+    /// stored value and its label. Faithful to the ancestor format's
+    /// inline enums.
+    #[serde(default)]
+    pub options: Vec<String>,
     /// `type: select` only - which field in each item is the option's
     /// stable id. Defaults to trying `_id` then `id`.
     #[serde(default)]
@@ -1204,9 +1210,12 @@ pub fn validate_questions(
                 .collect();
             for feature in &alternative.features {
                 for requirement in &feature.requirements {
-                    if requirement.kind == "select" && requirement.resource.is_none() {
+                    if requirement.kind == "select"
+                        && requirement.resource.is_none()
+                        && requirement.options.is_empty()
+                    {
                         anyhow::bail!(
-                            "question {:?} alternative {:?} feature {:?}: requirement {:?} is type: select but declares no resource to select from",
+                            "question {:?} alternative {:?} feature {:?}: requirement {:?} is type: select but declares neither a resource nor inline options",
                             question.id, alternative.name, feature.name, requirement.name
                         );
                     }