Support comment blocks inside liquid tags

[cappuc]

Summary

• Add line-based comment/endcomment block handling inside {% liquid %} tags.
• Preserve opaque comment contents and report unclosed blocks with the correct line number.
• Add integration coverage for valid, nested, whitespace-controlled, and invalid comment blocks.

Testing

• Integration tests covering liquid comment blocks and syntax errors.

Closes #56

[github-actions]

PHPBench comparison (PHP 8.2)

PHP 8.2 | Runner ubuntu24 | Base 60b7dbe | PR cac2f04 | 10 iterations x 20 revs | 1 warmup

Positive ops/s is faster. RSD above 5% is marked high.

Benchmark	Base ops/s	PR ops/s	Delta ops/s	RSD (base / PR)	Delta memory	Memory %
ThemeBench::benchParse	531.90 ops/s	526.85 ops/s	-0.95%	0.92% / 1.32%	-176.00 B	-0.00%
ThemeBench::benchRender	309.97 ops/s	308.73 ops/s	-0.40%	2.02% / 1.71%	-240.00 B	-0.00%
ThemeBench::benchStream	303.94 ops/s	309.94 ops/s	+1.97%	1.29% / 0.94%	-240.00 B	-0.00%
ThemeBench::benchTokenize	1,119.59 ops/s	1,123.73 ops/s	+0.37%	0.83% / 1.27%	-176.00 B	-0.00%

• Improved (> +2%): 0

• Neutral (within ±2%): 4

• Regressed (< -2%): 0

• Worst throughput regression: n/a

• Total memory change: -0.00%

• Regression threshold (PHPBENCH_MAX_REG): 5.00%

• Threshold status: PASSED

[github-actions]

PHPBench comparison (PHP 8.3)

PHP 8.3 | Runner ubuntu24 | Base 60b7dbe | PR cac2f04 | 10 iterations x 20 revs | 1 warmup

Positive ops/s is faster. RSD above 5% is marked high.

Benchmark	Base ops/s	PR ops/s	Delta ops/s	RSD (base / PR)	Delta memory	Memory %
ThemeBench::benchParse	485.85 ops/s	477.90 ops/s	-1.64%	1.89% / 1.71%	-176.00 B	-0.00%
ThemeBench::benchRender	289.61 ops/s	282.96 ops/s	-2.30%	2.16% / 2.49%	-240.00 B	-0.00%
ThemeBench::benchStream	285.80 ops/s	285.69 ops/s	-0.04%	1.95% / 1.29%	-240.00 B	-0.00%
ThemeBench::benchTokenize	1,125.47 ops/s	1,085.55 ops/s	-3.55%	2.66% / 2.53%	-176.00 B	-0.00%

• Improved (> +2%): 0

• Neutral (within ±2%): 2

• Regressed (< -2%): 2 (median -2.92%)

• Worst throughput regression: ThemeBench::benchTokenize (-3.55%)

• Total memory change: -0.00%

• Regression threshold (PHPBENCH_MAX_REG): 5.00%

• Threshold status: PASSED

[github-actions]

PHPBench comparison (PHP 8.4)

PHP 8.4 | Runner ubuntu24 | Base 60b7dbe | PR cac2f04 | 10 iterations x 20 revs | 1 warmup

Positive ops/s is faster. RSD above 5% is marked high.

Benchmark	Base ops/s	PR ops/s	Delta ops/s	RSD (base / PR)	Delta memory	Memory %
ThemeBench::benchParse	334.01 ops/s	323.38 ops/s	-3.18%	1.70% / 1.42%	-363.45 KiB	-4.07%
ThemeBench::benchRender	205.23 ops/s	203.70 ops/s	-0.75%	1.32% / 1.22%	+122.76 KiB	+1.38%
ThemeBench::benchStream	206.76 ops/s	206.38 ops/s	-0.18%	1.56% / 1.49%	-29.34 KiB	-0.37%
ThemeBench::benchTokenize	988.35 ops/s	959.56 ops/s	-2.91%	2.90% / 2.05%	+174.23 KiB	+2.33%

• Improved (> +2%): 0

• Neutral (within ±2%): 2

• Regressed (< -2%): 2 (median -3.05%)

• Worst throughput regression: ThemeBench::benchParse (-3.18%)

• Total memory change: -0.29%

• Regression threshold (PHPBENCH_MAX_REG): 5.00%

• Threshold status: PASSED

[github-actions]

PHPBench comparison (PHP 8.5)

PHP 8.5 | Runner ubuntu24 | Base 60b7dbe | PR cac2f04 | 10 iterations x 20 revs | 1 warmup

Positive ops/s is faster. RSD above 5% is marked high.

Benchmark	Base ops/s	PR ops/s	Delta ops/s	RSD (base / PR)	Delta memory	Memory %
ThemeBench::benchParse	309.53 ops/s	300.56 ops/s	-2.90%	1.80% / 1.87%	-306.50 KiB	-3.39%
ThemeBench::benchRender	192.23 ops/s	195.15 ops/s	+1.52%	1.59% / 2.00%	-134.84 KiB	-1.50%
ThemeBench::benchStream	193.73 ops/s	197.74 ops/s	+2.07%	2.21% / 1.99%	+117.61 KiB	+1.48%
ThemeBench::benchTokenize	861.88 ops/s	875.76 ops/s	+1.61%	1.50% / 1.65%	-176.00 B	-0.00%

• Improved (> +2%): 1 (median +2.07%)

• Neutral (within ±2%): 2

• Regressed (< -2%): 1 (median -2.90%)

• Worst throughput regression: ThemeBench::benchParse (-2.90%)

• Total memory change: -0.97%

• Regression threshold (PHPBENCH_MAX_REG): 5.00%

• Threshold status: PASSED