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/sample_data/pug/test/run-syntax-errors.test.js

@@ -0,0 +1,43 @@
+const assert = require('assert');
+const fs = require('fs');
+const runUtils = require('./run-utils');
+const pug = require('../');
+
+const anti = runUtils.findCases(__dirname + '/anti-cases');
+
+describe('certain syntax is not allowed and will throw a compile time error', function() {
+  anti.forEach(function(test) {
+    var name = test.replace(/[-.]/g, ' ');
+    it(name, function() {
+      var path = __dirname.replace(/\\/g, '/') + '/anti-cases/' + test + '.pug';
+      var str = fs.readFileSync(path, 'utf8');
+      try {
+        var fn = pug.compile(str, {
+          filename: path,
+          pretty: true,
+          basedir: __dirname + '/anti-cases',
+          filters: runUtils.filters,
+        });
+      } catch (ex) {
+        if (!ex.code) {
+          throw ex;
+        }
+        assert(ex instanceof Error, 'Should throw a real Error');
+        assert(
+          ex.code.indexOf('PUG:') === 0,
+          'It should have a code of "PUG:SOMETHING"'
+        );
+        assert(
+          ex.message.replace(/\\/g, '/').indexOf(path) === 0,
+          'it should start with the path'
+        );
+        assert(
+          /:\d+$/m.test(ex.message.replace(/\\/g, '/')),
+          'it should include a line number.'
+        );
+        return;
+      }
+      throw new Error(test + ' should have thrown an error');
+    });
+  });
+});