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

playground/benchmark.zig

@@ -0,0 +1,66 @@
+// benchmark.zig - Benchmark for pugz (Zig Pug implementation)
+//
+// This benchmark matches the JavaScript pug benchmark for comparison
+// Uses exact same templates as packages/pug/support/benchmark.js
+
+const std = @import("std");
+const pug = @import("../pug.zig");
+
+const MIN_ITERATIONS: usize = 200;
+const MIN_TIME_NS: u64 = 200_000_000; // 200ms minimum
+
+fn benchmark(comptime name: []const u8, template: []const u8, iterations: *usize, elapsed_ns: *u64) !void {
+    const allocator = std.heap.page_allocator;
+
+    // Warmup
+    for (0..10) |_| {
+        var result = try pug.compile(allocator, template, .{});
+        result.deinit(allocator);
+    }
+
+    var timer = try std.time.Timer.start();
+
+    var count: usize = 0;
+    while (count < MIN_ITERATIONS or timer.read() < MIN_TIME_NS) {
+        var result = try pug.compile(allocator, template, .{});
+        result.deinit(allocator);
+        count += 1;
+    }
+
+    const elapsed = timer.read();
+    iterations.* = count;
+    elapsed_ns.* = elapsed;
+
+    const ops_per_sec = @as(f64, @floatFromInt(count)) * 1_000_000_000.0 / @as(f64, @floatFromInt(elapsed));
+    std.debug.print("{s}: {d:.0}\n", .{ name, ops_per_sec });
+}
+
+pub fn main() !void {
+    var iterations: usize = 0;
+    var elapsed_ns: u64 = 0;
+
+    // Tiny template - exact match to JS: 'html\n  body\n    h1 Title'
+    const tiny = "html\n  body\n    h1 Title";
+    try benchmark("tiny", tiny, &iterations, &elapsed_ns);
+
+    // Small template - exact match to JS (note trailing \n on each line)
+    const small =
+        "html\n" ++
+        "  body\n" ++
+        "    h1 Title\n" ++
+        "    ul#menu\n" ++
+        "      li: a(href=\"#\") Home\n" ++
+        "      li: a(href=\"#\") About Us\n" ++
+        "      li: a(href=\"#\") Store\n" ++
+        "      li: a(href=\"#\") FAQ\n" ++
+        "      li: a(href=\"#\") Contact\n";
+    try benchmark("small", small, &iterations, &elapsed_ns);
+
+    // Medium template - Array(30).join(str) creates 29 copies in JS
+    const medium = small ** 29;
+    try benchmark("medium", medium, &iterations, &elapsed_ns);
+
+    // Large template - Array(100).join(str) creates 99 copies in JS
+    const large = small ** 99;
+    try benchmark("large", large, &iterations, &elapsed_ns);
+}