perf(build): budget the runtime on what ships, not on source bytes

The runtime budgets measured raw source, which counts comments -- and the
production build minifies, so comments cost a visitor nothing. The metric
therefore rewarded deleting explanatory comments over writing smaller code,
and could not tell a real feature from a wall of prose.

They now measure the minified output, which is what is actually served:
/__wrnexus/reactive.js is its own file, minified, with an immutable year-long
cache. The reactive runtime is 69684 minified against a 80000 budget, from
175246 raw -- roughly 21kB gzipped, fetched once.

Also fixes two real bugs found while testing the showcase:

  - object-valued props were serialised as a bare {...} attribute, which the
    compiler read as interpolation and tried to parse as JavaScript. That
    returned 500 for /components/navbar. Arrays start with [ and were never
    affected, which is why only object props broke. All 108 pages now render.

  - the runtime walked text nodes inside textarea, script and style, so a
    JSON sample in a textarea was evaluated away.

Navbar styles move out of ui.css into the component, matching the rest of the
navigation group. No declarations changed: 4519 before and after.

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

examples/component-showcase/app/pages/components/scrollspy.wrn

@@ -151,7 +151,7 @@ page ScrollspyDetail {
         <form class="playground-controls" data-playground-form>
           <header><div><span>Component props</span><strong>7 controls</strong></div><button type="reset"><span class="icon-[lucide--rotate-ccw] size-4" aria-hidden="true"></span>Reset</button></header>
           <div class="playground-fields"><label class="playground-field" for="playground-scrollspy-color"><span><strong>color</strong><small>string</small></span><select id="playground-scrollspy-color" name="pg_color"><option value="primary" selected>primary</option><option value="secondary">secondary</option><option value="success">success</option><option value="warning">warning</option><option value="danger">danger</option><option value="info">info</option></select></label><label class="playground-field" for="playground-scrollspy-size"><span><strong>size</strong><small>string</small></span><select id="playground-scrollspy-size" name="pg_size"><option value="default" selected>default</option><option value="xs">xs</option><option value="sm">sm</option><option value="md">md</option><option value="lg">lg</option><option value="xl">xl</option><option value="icon">icon</option><option value="icon-xs">icon-xs</option><option value="icon-sm">icon-sm</option><option value="icon-lg">icon-lg</option></select></label><label class="playground-field" for="playground-scrollspy-items"><span><strong>items</strong><small>unknown[]</small></span><textarea id="playground-scrollspy-items" name="pg_items" rows="5" spellcheck="false" data-playground-json>[
-  {
+  &#123;
     "id": "scrollspy-0-1",
     "key": "scrollspy-0-1",
     "value": "primary",
@@ -180,31 +180,31 @@ page ScrollspyDetail {
     "target": "_self",
     "ariaLabel": "Open primary workflow 1",
     "items": [
-      {
+      &#123;
         "label": "Nested option A",
         "value": "nested-a"
-      },
-      {
+      &#125;,
+      &#123;
         "label": "Nested option B",
         "value": "nested-b"
-      }
+      &#125;
     ],
     "links": [
-      {
+      &#123;
         "label": "Documentation",
         "href": "#documentation"
-      },
-      {
+      &#125;,
+      &#123;
         "label": "API reference",
         "href": "#api-reference"
-      }
+      &#125;
     ],
     "values": [
       "Included",
       "Standard"
     ]
-  },
-  {
+  &#125;,
+  &#123;
     "id": "scrollspy-0-2",
     "key": "scrollspy-0-2",
     "value": "secondary",
@@ -233,30 +233,30 @@ page ScrollspyDetail {
     "target": "_self",
     "ariaLabel": "Open primary workflow 2",
     "items": [
-      {
+      &#123;
         "label": "Nested option A",
         "value": "nested-a"
-      },
-      {
+      &#125;,
+      &#123;
         "label": "Nested option B",
         "value": "nested-b"
-      }
+      &#125;
     ],
     "links": [
-      {
+      &#123;
         "label": "Documentation",
         "href": "#documentation"
-      },
-      {
+      &#125;,
+      &#123;
         "label": "API reference",
         "href": "#api-reference"
-      }
+      &#125;
     ],
     "values": [
       "Included",
       "Standard"
     ]
-  }
+  &#125;
 ]</textarea><em data-playground-error></em></label><label class="playground-field" for="playground-scrollspy-active"><span><strong>active</strong><small>string</small></span><input id="playground-scrollspy-active" name="pg_active" type="text" value="" /></label><label class="playground-field" for="playground-scrollspy-label"><span><strong>label</strong><small>string</small></span><input id="playground-scrollspy-label" name="pg_label" type="text" value="Scrollspy" /></label><label class="playground-field" for="playground-scrollspy-heading"><span><strong>heading</strong><small>string</small></span><input id="playground-scrollspy-heading" name="pg_heading" type="text" value="" /></label><label class="playground-field" for="playground-scrollspy-class"><span><strong>class</strong><small>string</small></span><input id="playground-scrollspy-class" name="pg_class" type="text" value="showcase-instance showcase-instance--1" /></label></div>
         </form>
       </div>