v1.2.0

✨ Feature — extend a component by patching its template

• A component extension can now patch its base's template instead of overriding it. Declare
  export const patch — a static array of ops — and skip writing your own template; the loader
  resolves the (local) base template, applies the ops, and compiles the result:

  // my-list.ts
  import List from './list';
  export const extend = List;
  export const patch = [
    { op: 'attr',    sel: '.weave-list__row', attr: 'on:dblclick={{ () => onRowDblClick(item) }}' },
    { op: 'prepend', sel: '[role]',           html: '<div class="count">{{ totalCount() }} total</div>' },
  ];
  export function setup(props, base) {
    return { ...base, totalCount: () => base.items().length, onRowDblClick: (i) => props.onOpen?.(i.value) };
  }

  Ops: attr / removeAttr, prepend / append, before / after, replace, remove, wrap.
  Selectors match by tag, .class, [attr], or [attr=value]; a selector that matches nothing is a
  loud build error. Inserted markup and added attributes are ordinary Weave template text ({{ }},
  on:, use:, @if/@for, nested components all work).
• It's build-time, so it's correct for reactive content — a patch on a @for row applies to every
  row, including ones added later (a runtime DOM patch would miss them). The extension compiles with the
  base's style hash, so the base's scoped CSS still applies.
• Two constraints: the base must be a local component (a published package ships no raw template
  — patch a local base, or use full override), and an extension uses either patches or a
  full-override template, never both.
• Known limitation: patch markup isn't type-checked by weave check yet (a typo in a patched
  expression surfaces at build/runtime, not in the editor). Full-override (#1) extensions are fully
  checked. See Extending a component.
• This completes RFC 0008 (both modes: #1 full override from 1.1.0,
  #3 patches here).