feat(compiler): compile client api blocks into the browser module

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

packages/compiler/src/client-codegen.ts

@@ -308,6 +308,32 @@ function _functionEntry(
   }`;
 }
 
+/**
+ * Client-mode api blocks become members of an `api` object in client scope.
+ *
+ * Only the response and error bodies are emitted; the declared field types are
+ * type-only and are consumed by the types generator instead. Anything
+ * TypeScript reaching this module would be a syntax error in the .mjs artifact.
+ */
+function apiBindings(ast: PageAst): string {
+  const members = ast.dataApis
+    .filter((block) => block.mode === "client" && block.sections)
+    .map((block) => {
+      const sections = block.sections!;
+      const response = sections.response.trim() || "return data;";
+      const error = sections.error.trim();
+      const failure = error
+        ? `(error) => { const status = error.status; const message = error.message; const data = error.data; ${error} }`
+        : `(error) => { throw error; }`;
+
+      return `    ${JSON.stringify(block.name)}: async (input) => context.callApi(${JSON.stringify(
+        block.path,
+      )}, ${JSON.stringify(block.method)}, input).then((data) => { ${response} }).catch(${failure})`;
+    });
+
+  return members.length ? `const api = {\n${members.join(",\n")}\n  };` : "";
+}
+
 export function generateBrowserModule(ast: PageAst): string {
   const functions = ast.runtimeFunctions.filter((fn) =>
     ["legacy", "client", "shared"].includes(fn.runtime),
@@ -365,6 +391,7 @@ function __wrnexusCreateClientFunctions(context) {
   const server = context.server;
   const props = context.props;
   const refs = context.refs;
+  ${apiBindings(ast)}
   const __wrnexusCommit = () => { ${sharedCommit} };
   const __wrnexusRestore = () => { ${sharedRestore} };
   ${!hasAuthoredCommit ? "const commit = __wrnexusCommit;" : ""}