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

REQUIREMENTS.md

@@ -599,6 +599,9 @@ what a valid business email is.
 ### req: test/004
 004	Repository-wide verification uses a resource-aware runner that caps Cargo build jobs and Rust test threads from available CPU and memory. User-requested concurrency cannot exceed the detected safe cap. Browser E2E runs as an isolated step and can be skipped explicitly when browser infrastructure is unavailable.
 
+### req: test/005
+005	Tests that inspect rendered HTML structure, attributes, escaping, or ordering use DOM-aware parsing such as `scraper` or existing local HTML parsing helpers. Raw string assertions are reserved for tiny literal payload checks where parsing would add noise. [north_star]
+
 ---
 
 ## check
@@ -839,6 +842,19 @@ All forms support returning `impl IntoEffect` and compose through tuples.
 
 ---
 
+## style
+
+### req: style/001
+001	Plain CSS and SCSS own appearance. slhx-build discovers static class tokens from `.heml`, `.css`, and `.scss` build inputs and generates `CssClass` constants so Rust can reference known classes without raw strings. slhx does not parse selectors for behavior, cascade policy, or layout semantics. [north_star]
+
+### req: style/002
+002	Generated class constants are ergonomic references only: they do not create a CSS framework, require a framework project structure, or make dynamic class expressions compile-time facts. Unknown Rust class references fail by normal Rust name resolution when the generated constant is absent. [north_star]
+
+### req: style/003
+003	When a hemplate dynamic class attribute needs more than one class token, Rust passes a displayable list of generated `CssClass` values as view data. Rust should not assemble ad hoc class strings for known style tokens. [north_star]
+
+---
+
 ## convention
 
 ### req: convention/001