feat(style): generate checked class tokens

Add a boring CSS/SCSS class-token surface: slhx-build discovers static class tokens from hemplate/templates/stylesheets and emits generated CssClass constants. Add CssClasses for hemplate +class/view data and migrate techdemo dynamic/effect fragments toward hemplate-owned views with DOM-aware assertions.

req: style/001

req: style/002

req: style/003

req: html_safety/002

req: view/001

req: test/005

examples/techdemo/templates/partials/activity_feed.heml

@@ -0,0 +1,3 @@
+<ol class="activity">
+  <li h-for="item in &self.items">{+ item +}</li>
+</ol>

examples/techdemo/templates/partials/architecture_activity.heml

@@ -0,0 +1,5 @@
+<ol class="activity">
+  <li>Clicked a real anchor</li>
+  <li>Fetched HTML with X-SLHX-Partial</li>
+  <li>Preserved native fallback semantics</li>
+</ol>

examples/techdemo/templates/partials/architecture_board.heml

@@ -0,0 +1,5 @@
+<div class="lanes">
+  <section class="lane"><h3>hemplate</h3><p>Owns syntax and Surface facts.</p></section>
+  <section class="lane"><h3>slhx-build</h3><p>Generates resources and lowering tables.</p></section>
+  <section class="lane"><h3>runtime</h3><p>Executes compact EffectBatch ops.</p></section>
+</div>

examples/techdemo/templates/partials/architecture_hero.heml

@@ -0,0 +1,5 @@
+<div class="metrics">
+  <div class="metric"><strong>1</strong><span>template source of truth</span></div>
+  <div class="metric"><strong>0</strong><span>CSS selectors in handlers</span></div>
+  <div class="metric"><strong>∞</strong><span>typed composition through tuples</span></div>
+</div>

examples/techdemo/templates/partials/architecture_inspector.heml

@@ -0,0 +1 @@
+<div class="inspector-row"><b>Page swap</b><br>This route was fetched as a partial and rendered through the same root.</div>

examples/techdemo/templates/partials/live_feed.heml

@@ -0,0 +1 @@
+<div class="live-row"><strong>SSE tick #{+ self.tick +}</strong><br>Server streamed a typed EffectBatch into <code>slots::live_feed</code>.</div>