feat: add @TypeOf type hints for compiled templates

- Add TypeHint node type in parser for //- @TypeOf(field): type syntax
- Support scalar types (f32, i32, bool, etc.) and array/struct types
- Use helpers.appendValue() for non-string typed fields
- Filter out loop variable references from Data struct fields
- Preserve @TypeOf comments during comment stripping

Example usage:
  //- @TypeOf(subtotal): f32
  span $#{subtotal}

  //- @TypeOf(items): []{name: []const u8, price: f32}
  each item in items
    h3 #{item.name}

examples/demo/src/main.zig

@@ -55,7 +55,7 @@ const CartItem = struct {
 
 const Cart = struct {
     items: []const CartItem,
-    subtotal: []const u8,
+    subtotal: f32,
     shipping: []const u8,
     discount: ?[]const u8 = null,
     discountCode: ?[]const u8 = null,
@@ -189,7 +189,7 @@ const sample_cart_items = [_]CartItem{
 
 const sample_cart = Cart{
     .items = &sample_cart_items,
-    .subtotal = "209.98",
+    .subtotal = 209.98,
     .shipping = "0",
     .tax = "18.90",
     .total = "228.88",
@@ -309,11 +309,17 @@ fn productDetail(app: *App, req: *httpz.Request, res: *httpz.Response) !void {
 fn cart(app: *App, _: *httpz.Request, res: *httpz.Response) !void {
     const html = if (USE_COMPILED_TEMPLATES) blk: {
         const templates = @import("templates");
-        break :blk try templates.pages_cart.render(res.arena, .{
-            .cartCount = "2",
-            .subtotal = sample_cart.subtotal,
-            .tax = sample_cart.tax,
-            .total = sample_cart.total,
+        const Data = templates.pages_cart.Data;
+        break :blk try templates.pages_cart.render(res.arena, Data{
+            .cartCount = "3",
+            .cartItems = &.{
+                .{ .variant = "Black", .name = "Wireless Headphones", .price = 79.99, .quantity = 1, .total = 79.99 },
+                .{ .variant = "Silver", .name = "Laptop", .price = 500.00, .quantity = 1, .total = 500.00 },
+                .{ .variant = "RGB", .name = "Mechanical Keyboard", .price = 129.99, .quantity = 1, .total = 129.99 },
+            },
+            .subtotal = 709.98,
+            .tax = 63.90,
+            .total = 773.88,
         });
     } else app.view.render(res.arena, "pages/cart", .{
         .title = "Shopping Cart",

examples/demo/views/pages/cart.pug

@@ -14,17 +14,18 @@ block content
       .cart-layout
         .cart-main
           .cart-items
+            //- @TypeOf(cartItems): []{name: []const u8, variant: []const u8, price: f32, quantity: u16, total: f32}
             each item in cartItems
               .cart-item
                 .cart-item-info
-                  h3 #{name}
-                  p.text-muted #{variant}
-                  span.cart-item-price $#{price}
+                  h3 #{item.name}
+                  p.text-muted #{item.variant}
+                  span.cart-item-price $#{item.price}
                 .cart-item-qty
                   button.qty-btn -
-                  input.qty-input(type="text" value=quantity)
+                  input.qty-input(type="text" value=item.quantity)
                   button.qty-btn +
-                .cart-item-total $#{total}
+                .cart-item-total $#{item.total}
                 button.cart-item-remove x
 
           .cart-actions
@@ -34,14 +35,17 @@ block content
           h3 Order Summary
           .summary-row
             span Subtotal
+            //- @TypeOf(subtotal): f32
             span $#{subtotal}
           .summary-row
             span Shipping
             span.text-success Free
           .summary-row
             span Tax
+            //- @TypeOf(tax): f32
             span $#{tax}
           .summary-row.summary-total
             span Total
+            //- @TypeOf(total): f32
             span $#{total}
           a.btn.btn-primary.btn-block(href="/checkout") Proceed to Checkout