feat(component): add @choojs/component — nanocomponent + on-load as ES classes

Ported from nanocomponent 6.6.0 and on-load 3.4.1 (MIT) with attribution:
render/update/morph lifecycle, proxy nodes with isSameNode identity, and
the MutationObserver-driven load/unload hooks. This class is the intended
island/hydration boundary for later phases. @choojs/core exposes ./timing
as a subpath for the instrumentation calls.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014NgfSjHE11oFpoSnLVKLXd

packages/core/package.json

@@ -4,7 +4,8 @@
   "description": "A 4kb framework for creating sturdy frontend applications",
   "type": "module",
   "exports": {
-    ".": "./index.js"
+    ".": "./index.js",
+    "./timing": "./lib/timing.js"
   },
   "files": [
     "index.js",