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

benchmarks/templates/if-expression.json

@@ -0,0 +1,28 @@
+{
+  "accounts": [
+    {
+      "balance": 0,
+      "balanceFormatted": "$0.00",
+      "status": "open",
+      "negative": false
+    },
+    {
+      "balance": 10,
+      "balanceFormatted": "$10.00",
+      "status": "closed",
+      "negative": false
+    },
+    {
+      "balance": -100,
+      "balanceFormatted": "$-100.00",
+      "status": "suspended",
+      "negative": true
+    },
+    {
+      "balance": 999,
+      "balanceFormatted": "$999.00",
+      "status": "open",
+      "negative": false
+    }
+  ]
+}