bench: feature-on baseline for raw_json (keeps field stripping)

[stormslowly]

Why

Baseline for measuring the cost of PackageJson::raw_json(). The benchmark previously built without package_json_raw_json_api, so the init_serde_json materialization path was never compiled and CodSpeed could not see it.

This PR only enables the feature in the benchmark build. Source behavior is unchanged — JSONCell::try_new still strips description/keywords/scripts/dependencies/… (current main behavior).

So this PR's CodSpeed numbers are the feature-on + strip baseline.

What

• benchmark.yml: cargo codspeed build → cargo codspeed build --features package_json_raw_json_api
• No source change.

Companion PR

The change PR #268 is stacked on this branch and removes the stripping. Its CodSpeed report compares directly against this baseline, so reviewers see the keep-vs-strip delta in one table.

This pair is for measurement/review only — not intended to merge as-is.

[codspeed-hq]

Merging this PR will degrade performance by 16.16%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
❌ 6 regressed benchmarks
✅ 5 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Memory	resolver[single-thread]	8.3 MB	12.8 MB	-35.29%
❌	Memory	resolver[[single-threaded]resolve with many extensions]	13.4 MB	17.9 MB	-25.25%
❌	Simulation	resolver[single-thread]	51.3 ms	62 ms	-17.34%
❌	Simulation	resolver[[multi-threaded]resolve]	60.4 ms	71.3 ms	-15.3%
❌	Memory	resolver[tsconfig resolve]	27.9 KB	31 KB	-10.04%
❌	Simulation	resolver[[single-threaded]resolve with many extensions]	126.6 ms	137.6 ms	-8.02%
⚡	Memory	resolver[pnp resolve]	9.1 KB	8.8 KB	+3.92%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing bench/raw-json-feature-on-baseline (b9e212a) with main (cb42e9a)}