Add native batch text URL rewrite API

[adamziel]

What it does

Adds wp_native_apis_rewrite_text_url_bases() to the wp_native_apis extension. The function rewrites URL bases across a whole text value in one native call using a compact from\x1fto\x1e... mapping string.

Rationale

Reprint currently has to drive URL detection and replacement from PHP one URL at a time. In PHP.wasm, that keeps the hot URL rewrite path split across many PHP/native boundary crossings. This adds a coarse native primitive that can rewrite one decoded value in a single call.

Implementation

The host PHP extension exposes the function through the Rust-backed ext-php-rs module and reuses the existing Rust URL-in-text candidate scanner and validation logic. It applies base URL replacements in one pass over the original text and preserves bare-domain and protocol-relative URL forms.

The PHP.wasm extension still builds through native_apis_shim.c, so this PR also adds the same public function to that C shim. That gives Playground/Reprint a real PHP.wasm fast path instead of only smoke-test classes.

The verifier and Playground smoke blueprint now check that the extension registers the function and that a simple base replacement works.

Benchmarks

Measured from Reprint PR adamziel/reprint#216, CI run https://github.com/adamziel/reprint/actions/runs/26067523070/attempts/3.

Focused case: StructuredDataUrlRewriter rewrites 10,000 URLs across 556,690 scanned bytes.

Runtime	Userland	Native extension	Delta
Host PHP	2968.918 ms	6.743 ms	-99.8%, about 440x faster
PHP.wasm 8.4	7616.311 ms	7.632 ms	-99.9%, about 998x faster

These are single-run CI measurements, so treat them as directional.

Testing instructions

Run locally:

cd extensions/native-apis
cargo fmt --check
cargo test
cd ../..
php -l extensions/native-apis/tests/verify-native-apis.php
php -r '$json=json_decode(file_get_contents("extensions/native-apis/playground/blueprint.json"), true); if (!is_array($json)) { fwrite(STDERR, json_last_error_msg()."\n"); exit(1); } $tmp=tempnam(sys_get_temp_dir(), "native-blueprint-"); file_put_contents($tmp, $json["steps"][0]["data"]); passthru("php -l " . escapeshellarg($tmp), $code); unlink($tmp); exit($code);'
git diff --check

Local results from this branch:

cargo test: 89 passed
php -l extensions/native-apis/tests/verify-native-apis.php: no syntax errors
playground blueprint embedded PHP: no syntax errors
git diff --check: passed

I could not build the PHP extension locally because this environment has no php-config and no package manager to install PHP development headers. GitHub Actions builds and verifies both the host PHP extension and the PHP.wasm extension.

[adamziel]

Rebased this stack on current trunk after #283 landed and re-ran the same post-content sample benchmark.

Sample: 5,000 post_content values, 16.85 MB decoded, PHP.wasm 8.4, wp_native_apis loaded, output hash 44c9750cb310ad822ce73840290c647e609b78ee047365b60f9f123aeed5d9bc for both branches.

Branch	Runs	Median	Delta
#282 rebased on trunk/#283	3.773 s, 3.655 s, 3.642 s	3.655 s	baseline
#284 stacked on rebased #282	2.632 s, 2.532 s, 2.448 s	2.532 s	30.7% faster

This did not confirm the hypothesis that the stacked native batch text rewrite has no meaningful improvement after #283. It is still materially faster on this content sample.

Caveat: the rebased native-extension CI is currently failing URL text parity tests in the native-extension job, so this stack is not merge-ready as-is.