feat(build): generate page-boundary helper

Expose generated ui::page as the canonical page-boundary rendering helper and move the Workout golden path and docs off beginner-visible ui::render calls.

req: public_api/002

req: codegen/002

req: canonical_authoring/006

README.md

@@ -34,7 +34,7 @@ For beginner and production-shaped app code, stay on this path. req: public_api/
 ## Mental model: render → slot/key → effect → runtime
 
 - **Render:** hemplate renders Rust view structs into checked HTML. App code
-  normally reaches rendering through generated helpers or `hemx::page(...)` at a
+  normally reaches rendering through generated `ui::page(...)` helpers at a
   server page boundary, not raw HTML construction. req: html_safety/002 req: view/001
 - **Slot/key:** a generated slot names the target, and a generated keyed slot
   also carries the stable row key. A list target inside `h-for` must have a

docs/recipes/deploy-versioning.md

@@ -99,9 +99,9 @@ persistence or cross-version addressing contract. req: abi/005
 For v1, document changes in three buckets:
 
 - **Beginner API:** generated helpers, `#[hemx::app]`, `#[hemx::component]`,
-  `#[hemx::handler]`, `#[hemx::form]`, `hemx::page`, tuple `IntoEffect`, and
-  `Result<impl IntoEffect, E>` mapping. Breaking changes require a major version
-  or an explicit migration note.
+  `#[hemx::handler]`, `#[hemx::form]`, generated page-boundary rendering, tuple
+  `IntoEffect`, and `Result<impl IntoEffect, E>` mapping. Breaking changes
+  require a major version or an explicit migration note.
 - **Wire/runtime ABI:** EffectBatch schema, runtime ABI version, and fingerprint
   inputs. Incompatible changes must bump ABI versions and fail closed at runtime.
 - **Advanced escape hatches:** raw effects, manual registries, low-level ids,

docs/versioning.md

@@ -15,8 +15,8 @@ changes:
 - `#[hemx::surface]`, `#[hemx::app]`, `#[hemx::component]`, `#[hemx::handler]`,
   and `#[hemx::form]`
 - generated component helpers for slots, keyed partials, forms, handles, page
-  targets, class tokens, and events
-- `hemx::page(...)` for page-boundary rendering
+  targets, page-boundary rendering, class tokens, and events
+- `hemx::page(...)` only at explicit server shell boundaries
 - tuple `IntoEffect` composition
 - `Result<impl IntoEffect, E>` handlers with `IntoHandlerFailure`
 - generated form commands such as `clear`, `reset`, `error`, and `focus`

examples/workout/src/lib.rs

@@ -627,7 +627,7 @@ pub struct AppShell {
 }
 
 pub fn page(runtime_src: &'static str, state: &WorkoutState) -> Html {
-    ui::render(&AppShell {
+    ui::page(&AppShell {
         runtime_src,
         body: render(state),
     })
@@ -683,7 +683,7 @@ pub fn view(state: &WorkoutState) -> Workout {
 }
 
 pub fn render(state: &WorkoutState) -> Html {
-    ui::render(&view(state))
+    ui::page(&view(state))
 }
 
 #[derive(Clone, Debug)]

hemx-build/src/lib.rs

@@ -743,6 +743,9 @@ impl Resources {
             "{pad}    ::hemx::__private::html_trusted(lower(html))\n"
         ));
         out.push_str(&format!("{pad}}}\n\n"));
+        out.push_str(&format!(
+            "{pad}pub fn page(view: &impl ::hemplate::Hemplate) -> ::hemx::Html {{ render(view) }}\n\n"
+        ));
         out.push_str(&format!("{pad}#[doc(hidden)]\n"));
         out.push_str(&format!("{pad}pub fn render_html(view: &impl ::hemplate::Hemplate) -> ::hemx::Html {{ render(view) }}\n\n"));
         out.push_str(&format!("{pad}#[doc(hidden)]\n"));
@@ -1733,6 +1736,7 @@ mod tests {
         assert!(
             generated.contains("pub fn render(view: &impl ::hemplate::Hemplate) -> ::hemx::Html")
         );
+        assert!(generated.contains("pub fn page(view: &impl ::hemplate::Hemplate) -> ::hemx::Html"));
         assert!(generated.contains(
             "#[doc(hidden)]\npub fn render_html(view: &impl ::hemplate::Hemplate) -> ::hemx::Html"
         ));
@@ -1845,6 +1849,9 @@ mod tests {
         assert!(
             generated.contains("\npub fn render(view: &impl ::hemplate::Hemplate) -> ::hemx::Html")
         );
+        assert!(
+            generated.contains("\npub fn page(view: &impl ::hemplate::Hemplate) -> ::hemx::Html")
+        );
         assert!(generated.contains("\n#[doc(hidden)]\npub fn render_html(view: &impl ::hemplate::Hemplate) -> ::hemx::Html"));
         assert!(generated.contains("\npub fn put<T>(slot: ::hemx::advanced::Slot<T>, view: &impl ::hemplate::Hemplate) -> ::hemx::advanced::Effect"));
         assert!(generated.contains("\npub fn append<K, T>(slot: ::hemx::advanced::KeyedSlot<K, T>, key: K, view: &impl ::hemplate::Hemplate) -> ::hemx::advanced::Effect"));
@@ -1858,6 +1865,9 @@ mod tests {
         assert!(generated.contains("    pub const todos: SlotTarget<::std::string::String> = SlotTarget::new(super::advanced::slots::todos);"));
         assert!(generated.contains("    pub use self::targets::todos;"));
         assert!(generated.contains("    #[doc(hidden)]\n    pub fn lower_html"));
+        assert!(
+            generated.contains("    pub fn page(view: &impl ::hemplate::Hemplate) -> ::hemx::Html")
+        );
         assert!(generated.contains("    #[doc(hidden)]\n    pub fn render_html(view: &impl ::hemplate::Hemplate) -> ::hemx::Html"));
         assert!(
             generated.contains("    pub fn static_fragment(html: &'static str) -> ::hemx::Html")