fix(csr,ui): deliver component outputs to parent bindings

An output only reaches a parent @binding when the component calls
output.<name>(). Two separate faults meant most of the library never got
there, and both failed silently at each end.

HTML lowercases attribute names, so a parent's @sizeChange registered under
"sizechange" while the component emitted "sizeChange". The lookup missed, fell
through to a DOM dispatch, and the binding was never invoked. That made all 17
camelCase outputs undeliverable -- DataTable.pageChange and .rowClick,
Map.markerClick, ChatBubble.messageClick, LayoutSplitter.sizeChange and the
rest. invokeComponentOutput now falls back to a case-insensitive lookup, and a
csr test fails without it.

Separately, 18 components dispatched hand-built CustomEvents rather than
calling output.*. A bubbling event on the component's own root never reaches a
binding, because parent handlers live in a registry only the output proxy
reads. Card, Footer, Breadcrumb, Accordion, alert, Badge, AnnouncementBar,
AvatarGroup, ToggleCount and InputNumber now emit properly; Marquee, Map,
Timeline, List and SearchBox additionally declare the outputs they were
already firing. Dispatches on window are left alone -- that is how Toaster,
Modal and DataTable signal across component boundaries.

Verified in a browser both ways before and after: an AnnouncementBar
dispatching its own bubbling "dismiss" never reached a page-level @dismiss,
and reached it immediately once it called output.dismiss().

This corrects the audit, which called the LayoutSplitter failure "narrow and
unexplained" and read 32 dead outputs as 16 components needing a rebuild.
"Outputs work elsewhere" was an assumption; the components that worked
happened to use lowercase names and output.*. The dead-output ratchet drops
from 32 to 22, and a new test forbids the raw-CustomEvent pattern outright.

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

packages/csr/test/reactive.test.ts

@@ -631,6 +631,38 @@ test("component output handlers run in the parent scope", () => {
   expect(win.document.querySelector("#out")?.textContent).toBe("yes");
 });
 
+test("a camelCase output reaches a parent binding despite attribute lowercasing", () => {
+  /*
+   * A parent writes @sizeChange; HTML lowercases attribute names, so the
+   * handler registers under "sizechange" while the component emits
+   * "sizeChange". The lookup used to miss and fall through to a DOM dispatch,
+   * so the binding was never invoked and nothing reported an error. Every
+   * camelCase output in the library was undeliverable -- LayoutSplitter's
+   * sizeChange, DataTable's pageChange and rowClick, Map's markerClick and
+   * twelve more. Verified in a browser before and after the fix.
+   */
+  const win = mount(
+    `<div data-scope="saved: ''">` +
+      `<span id="out">{saved}</span>` +
+      `<div data-scope="n: 0" data-wrn-hydration="LayoutSplitter:x">` +
+      `<div data-wrn-events="sizechange" data-wrn-out-sizechange="saved = 'yes'">` +
+      `<button data-on-click="output.sizeChange({ size: 45 })">go</button>` +
+      `</div></div></div>`,
+  );
+
+  const target = win.document.querySelector("[data-wrn-events]") as unknown as {
+    __wrnexusOutputHandlers?: Record<string, Set<(payload: unknown) => unknown>>;
+  };
+  // The registry is keyed as the DOM gave it: lowercased, not as authored.
+  expect(Object.keys(target.__wrnexusOutputHandlers ?? {})).toContain("sizechange");
+  expect(target.__wrnexusOutputHandlers?.sizeChange).toBeUndefined();
+
+  // Emitting through the real output proxy, under the camelCase name the
+  // component actually writes, must still reach the parent.
+  (win.document.querySelector("button") as unknown as HTMLElement).click();
+  expect(win.document.querySelector("#out")?.textContent).toBe("yes");
+});
+
 // --- browser globals + regex literals in client expressions ----------------
 // Client functions and inline handlers are interpreted by the runtime's own
 // eval-free expression engine (so a strict CSP needs no unsafe-eval). Anything