perf: reduce JSX annotation string churn

[scttcper]

Summary

• use trace-driven optimizations in the JSX annotation hot path
• cache static JSX attribute identifiers and source-file/source-path string values to cut repeated hstr atom creation
• share the intrinsic element set through OnceLock and preallocate member-expression name strings to reduce allocation churn

Benchmarks

Scenario	Workload	Before (median)	After (median)	Speedup	Improvement
default-config	800 generated React components, 9 samples, 40 iterations/sample	2.604 ms	2.128 ms	1.22x	18.3% faster
source-path-config	Same workload with source_path_attr enabled	3.092 ms	2.367 ms	1.31x	23.4% faster

Benchmark Setup

• Host: Apple Silicon macOS 26.3.1
• Mode: release binaries
• Method: isolated before/after benchmark harnesses run against HEAD and this branch
• Profiler used to identify hot spots: macOS sample
• Hot spots addressed: repeated hstr atom creation while building JSX attrs and repeated string growth while building member-expression names

Validation

• cargo test

[Copilot]

Pull request overview

This PR optimizes the SWC plugin’s JSX annotation hot path by caching commonly reused AST string/identifier data and reducing repeated allocations while constructing JSX attributes and member-expression names.

Changes:

• Cache JSX attribute identifiers (IdentName) and source file/path strings (Str) inside the visitor to cut repeated atom creation during annotation.
• Share the default ignored-intrinsic-elements set via OnceLock to avoid per-visitor set construction.
• Reduce allocation churn when building JSX member-expression names by precomputing capacity and pushing into a single String.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/lib.rs	Cache attribute identifiers and source file/path strings; reserve attr capacity before pushing.
src/jsx_utils.rs	Optimize fragment detection and member-expression name building; add helpers that reuse cached IdentName/Str.
src/constants.rs	Initialize and reuse the ignored element set via a OnceLock static.
package.json	Bump npm package version to 1.13.0.

Comments suppressed due to low confidence (1)

src/lib.rs:313

• In transform_styled_call, the data-element attribute still uses create_jsx_attr(...), which rebuilds the IdentName each time. Since self.element_attr_ident is already cached for this purpose, consider switching this call to create_jsx_attr_with_ident(&self.element_attr_ident, ...) to avoid extra atom/allocation churn on the styled-component rewrite path as well.

        // Add data-element attribute using the styled component variable name
        attrs.push(create_jsx_attr(
            self.config.element_attr_name(),
            &styled_component_name,
        ));

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