chore(eslint): exclude docs-site content from linting

Per-composable demos (demo.vue) and hand-authored doc sections (docs/*.vue) are unpublished docs-site content co-located in packages for the extractor. Ignore **/docs/** and **/demo.vue: they aren't library source, and non-Vue packages can't parse .vue at all (parse error in configs/eslint).

configs/eslint/src/presets/base.ts

@@ -20,6 +20,11 @@ export const ignores: FlatConfigArray = [
       '**/.output/**',
       '**/storybook-static/**',
       '**/*.min.*',
+      // Hand-authored docs-site content co-located in packages (intro/guide .vue
+      // pages and per-composable demos). Not shipped source; lints against the
+      // docs app's own toolchain, and non-Vue packages can't even parse .vue.
+      '**/docs/**',
+      '**/demo.vue',
     ],
   },
 ];