feat(api): streamline generated app authoring

Move the canonical examples toward generated component-root helpers, typed form decoding, async/state handler registration, and derive-driven app/component registry wiring. Tighten requirements and diagnostics for the server-first, selectorless authoring path.

Verified with cargo run -p slhx-xtask -- test, cargo check --workspace, redgate list, redgate refs, redgate health --strict, and git diff --check.

req: canonical/001

req: canonical/003

req: canonical/004

req: dx/002

req: derive_app/001

req: component/003

req: form/004

req: axum_integration/003

examples/techdemo/src/lib.rs

@@ -3,11 +3,11 @@ pub mod ui {}
 
 #[cfg(test)]
 mod tests {
-    use super::ui::control_center::{forms, handles, slots, targets};
-    use super::ui::issue_card::handles as card_handles;
+    use super::ui::control_center::{hero_metrics, launch_work, launch_work_form, notice};
+    use super::ui::issue_card::advance_work;
     use super::ui::issue_lane::events as lane_events;
     use hemplate::Hemplate;
-    use slhx::{Effect, IntoEffect, Payload};
+    use slhx::IntoEffect;
     use slhx_test::inspect;
 
     #[derive(Hemplate)]
@@ -30,14 +30,14 @@ mod tests {
     fn techdemo_uses_generated_slots_for_multi_target_updates() {
         fn update() -> impl IntoEffect {
             (
-                targets::hero_metrics.put(&FastMetric { label: "fast" }),
-                slots::notice.text("typed"),
+                hero_metrics.put(&FastMetric { label: "fast" }),
+                notice.text("typed"),
             )
         }
 
         let batch = inspect(update());
-        assert!(batch.has_slot(slots::hero_metrics));
-        assert!(batch.has_slot(slots::notice));
+        assert!(batch.has_target(hero_metrics));
+        assert!(batch.has_target(notice));
     }
 
     // req: examples/001 req: form/001 req: form/004 req: form/006 req: derive_handler/003
@@ -45,22 +45,21 @@ mod tests {
     fn techdemo_form_handler_is_checked_against_hemplate_form() {
         #[slhx::handler]
         fn launch_work(_form: slhx::Form<LaunchWork>) -> impl IntoEffect {
-            slots::notice.text("queued")
+            notice.text("queued")
         }
 
         let batch = inspect(launch_work(LaunchWork::FORM));
 
-        assert!(batch.has_slot(slots::notice));
-        assert!(matches!(batch.ops(), [Effect::Put { payload: Payload::Text(_), .. }]));
+        assert!(batch.updates_text(notice));
     }
 
     // req: examples/001 req: form/002 req: codegen/003
     #[test]
     fn techdemo_exports_form_and_interaction_handles() {
-        assert_ne!(handles::launch_work.id(), card_handles::advance_work.id());
+        assert_ne!(launch_work.id(), advance_work.id());
         assert_eq!(
-            forms::launch_work.field("title").resource,
-            forms::launch_work.id()
+            launch_work_form.field("title").resource,
+            launch_work_form.id()
         );
     }
 
@@ -68,9 +67,7 @@ mod tests {
     #[test]
     fn techdemo_exports_generated_event_constants() {
         assert_eq!(lane_events::drop.as_str(), "drop");
-        assert!(matches!(
-            slhx::event(lane_events::drop, "card-1"),
-            Effect::Emit { name, payload } if name == "drop" && payload == "card-1"
-        ));
+        let event = inspect(lane_events::drop.emit("card-1"));
+        assert!(event.emits("drop", "card-1"));
     }
 }