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/metric-grid.wrn

@@ -156,7 +156,7 @@ page MetricGridDetail {
         <form class="playground-controls" data-playground-form>
           <header><div><span>Component props</span><strong>13 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-metric-grid-items"><span><strong>items</strong><small>unknown[]</small></span><textarea id="playground-metric-grid-items" name="pg_items" rows="5" spellcheck="false" data-playground-json>[
-  {
+  &#123;
     "label": "Public services",
     "value": "24",
     "description": "Citizen-facing services available online.",
@@ -165,8 +165,8 @@ page MetricGridDetail {
     "trendLabel": "this release",
     "trendDirection": "up",
     "color": "primary"
-  },
-  {
+  &#125;,
+  &#123;
     "label": "Police stations",
     "value": "126",
     "description": "Searchable station and jurisdiction entries.",
@@ -174,8 +174,8 @@ page MetricGridDetail {
     "trend": "Updated",
     "trendLabel": "today",
     "color": "info"
-  },
-  {
+  &#125;,
+  &#123;
     "label": "Availability",
     "value": "99.9",
     "suffix": "%",
@@ -185,7 +185,7 @@ page MetricGridDetail {
     "trendLabel": "30 days",
     "trendDirection": "positive",
     "color": "success"
-  }
+  &#125;
 ]</textarea><em data-playground-error></em></label><label class="playground-field" for="playground-metric-grid-columns"><span><strong>columns</strong><small>number</small></span><input id="playground-metric-grid-columns" name="pg_columns" type="number" value="3" /></label><label class="playground-field" for="playground-metric-grid-tabletColumns"><span><strong>tablet Columns</strong><small>number</small></span><input id="playground-metric-grid-tabletColumns" name="pg_tabletColumns" type="number" value="2" /></label><label class="playground-field" for="playground-metric-grid-mobileColumns"><span><strong>mobile Columns</strong><small>number</small></span><input id="playground-metric-grid-mobileColumns" name="pg_mobileColumns" type="number" value="1" /></label><label class="playground-field" for="playground-metric-grid-gap"><span><strong>gap</strong><small>string</small></span><select id="playground-metric-grid-gap" name="pg_gap"><option value="md" selected>md</option><option value="none">none</option><option value="sm">sm</option><option value="lg">lg</option><option value="xl">xl</option><option value="xs">xs</option><option value="2xl">2xl</option></select></label><label class="playground-toggle" for="playground-metric-grid-equalHeight"><span><strong>equal Height</strong><small>boolean</small></span><input id="playground-metric-grid-equalHeight" name="pg_equalHeight" type="checkbox" value="true" checked data-playground-boolean /><i aria-hidden="true"></i></label><label class="playground-toggle" for="playground-metric-grid-dividers"><span><strong>dividers</strong><small>boolean</small></span><input id="playground-metric-grid-dividers" name="pg_dividers" type="checkbox" value="true" data-playground-boolean /><i aria-hidden="true"></i></label><label class="playground-field" for="playground-metric-grid-size"><span><strong>size</strong><small>string</small></span><select id="playground-metric-grid-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-metric-grid-color"><span><strong>color</strong><small>string</small></span><select id="playground-metric-grid-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-metric-grid-variant"><span><strong>variant</strong><small>string</small></span><select id="playground-metric-grid-variant" name="pg_variant"><option value="default" selected>default</option><option value="panel">panel</option><option value="soft">soft</option></select></label><label class="playground-field" for="playground-metric-grid-maxWidth"><span><strong>max Width</strong><small>string</small></span><select id="playground-metric-grid-maxWidth" name="pg_maxWidth"><option value="full" selected>full</option><option value="compact">compact</option><option value="lg">lg</option><option value="xl">xl</option><option value="wide">wide</option><option value="2xl">2xl</option></select></label><label class="playground-field" for="playground-metric-grid-minItemWidth"><span><strong>min Item Width</strong><small>string</small></span><input id="playground-metric-grid-minItemWidth" name="pg_minItemWidth" type="text" value="" /></label><label class="playground-field" for="playground-metric-grid-class"><span><strong>class</strong><small>string</small></span><input id="playground-metric-grid-class" name="pg_class" type="text" value="showcase-instance showcase-instance--1" /></label></div>
         </form>
       </div>