Add ViewEngine for easy server integration

- ViewEngine manages views directory with path resolution
- Auto-loads mixins from views/mixins/ directory
- Simplifies template paths (relative to views dir, auto-adds extension)
- Updated example app to use ViewEngine
- Added example mixins (buttons.pug, cards.pug)
- Updated CLAUDE.md with ViewEngine documentation

src/root.zig

@@ -7,12 +7,33 @@
 //! - Attributes and text interpolation
 //! - Control flow (if/else, each, while)
 //! - Mixins and template inheritance
+//!
+//! ## Quick Start (Server Usage)
+//!
+//! ```zig
+//! const pugz = @import("pugz");
+//!
+//! // Initialize view engine once at startup
+//! var engine = try pugz.ViewEngine.init(allocator, .{
+//!     .views_dir = "src/views",
+//! });
+//! defer engine.deinit();
+//!
+//! // Render templates (use arena allocator per request)
+//! var arena = std.heap.ArenaAllocator.init(allocator);
+//! defer arena.deinit();
+//!
+//! const html = try engine.render(arena.allocator(), "pages/home", .{
+//!     .title = "Home",
+//! });
+//! ```
 
 pub const lexer = @import("lexer.zig");
 pub const ast = @import("ast.zig");
 pub const parser = @import("parser.zig");
 pub const codegen = @import("codegen.zig");
 pub const runtime = @import("runtime.zig");
+pub const view_engine = @import("view_engine.zig");
 
 // Re-export main types for convenience
 pub const Lexer = lexer.Lexer;
@@ -32,6 +53,9 @@ pub const Value = runtime.Value;
 pub const render = runtime.render;
 pub const renderTemplate = runtime.renderTemplate;
 
+// High-level API
+pub const ViewEngine = view_engine.ViewEngine;
+
 test {
     _ = @import("std").testing.refAllDecls(@This());
 }