fix: add scoped error logging for lexer/parser errors

- Add std.log.scoped(.pugz) to template.zig and view_engine.zig
- Log detailed error info (code, line, column, message) when parsing fails
- Log template path context in ViewEngine on parse errors
- Remove debug print from lexer, use proper scoped logging instead
- Move benchmarks, docs, examples, playground, tests out of src/ to project root
- Update build.zig and documentation paths accordingly
- Bump version to 0.3.1

tests/mixin_debug_test.zig

@@ -0,0 +1,23 @@
+// This test is imported by root.zig for testing
+const std = @import("std");
+const testing = std.testing;
+const mixin = @import("../mixin.zig");
+
+test "bindArguments - with default value in param" {
+    const allocator = testing.allocator;
+
+    var bindings = std.StringHashMapUnmanaged([]const u8){};
+    defer bindings.deinit(allocator);
+
+    // This is how it appears: params have default, args are the call args
+    try mixin.bindArguments(allocator, "text, type=\"primary\"", "\"Click Me\", \"primary\"", &bindings);
+
+    std.debug.print("\nBindings:\n", .{});
+    var iter = bindings.iterator();
+    while (iter.next()) |entry| {
+        std.debug.print("  {s} = '{s}'\n", .{entry.key_ptr.*, entry.value_ptr.*});
+    }
+
+    try testing.expectEqualStrings("Click Me", bindings.get("text").?);
+    try testing.expectEqualStrings("primary", bindings.get("type").?);
+}