Make native parser extension visible

[adamziel]

What changed

Reorganizes the root README so Quick start stays first and the optional Native MySQL Parser Extension is discoverable without taking over the landing flow. The README links to the GitHub Pages landing page with the published WASM release list, manifest links, “Run in Playground” buttons, and native extension details.

Also expands packages/php-ext-wp-mysql-parser/README.md with local build/load instructions, WASM artifact details, checksum verification steps, and benchmark commands. The benchmark scripts now run cleanly on PHP 8.4+, can emit JSON, report exact processed counts, and the parser benchmark goes through the integration loader so php -d extension=... measures the native parser path instead of accidentally staying on the pure-PHP classes.

Why

The native extension and WASM artifacts were hard to discover. This keeps the normal README quick start prominent while giving users a clear path to optional native-extension docs, Playground links, and reproducible benchmark commands.

Self-review fixes

• Fixed benchmark query counts to use an explicit processed counter instead of loop-index arithmetic.
• Fixed run-parser-benchmark.php to include the first query and to load through src/load.php, matching runtime native-vs-PHP class selection.
• Tightened docs so build commands do not leave readers in the package directory before repository-root verification commands.
• Added checksum verification commands and refreshed benchmark numbers, including native parser results.

Related Pages work

• GitHub Pages native-extension demo: Add native extension GitHub Pages demo #408 (merged)
• GitHub Pages release list + Playground CLI instructions: List WASM extension releases on GitHub Pages #409 (merged)
• GitHub Pages benchmark refresh: Update native extension benchmark data #410 (merged)
• Published page: https://wordpress.github.io/sqlite-database-integration/

Validation

• composer validate --no-check-all
• php -l packages/mysql-on-sqlite/tests/tools/run-lexer-benchmark.php
• php -l packages/mysql-on-sqlite/tests/tools/run-parser-benchmark.php
• php -l packages/mysql-on-sqlite/tests/tools/run-native-extension-benchmark.php
• php packages/mysql-on-sqlite/tests/tools/run-lexer-benchmark.php --json --limit=100
• php packages/mysql-on-sqlite/tests/tools/run-parser-benchmark.php --json --limit=100
• php packages/mysql-on-sqlite/tests/tools/run-native-extension-benchmark.php --json --limit=100
• php -d extension=/path/to/libwp_mysql_parser.dylib packages/mysql-on-sqlite/tests/tools/run-native-extension-benchmark.php --json --limit=100
• php -d extension=/path/to/libwp_mysql_parser.dylib packages/mysql-on-sqlite/tests/tools/run-parser-benchmark.php --json --limit=100
• Full benchmark rerun for published numbers: lexer PHP, parser PHP, native lexer, native parser.
• npx @wp-playground/cli@latest run-blueprint --php=8.4 --php-extension=https://wordpress.github.io/sqlite-database-integration/wp_mysql_parser-wasm-extension/latest/manifest.json --blueprint=https://wordpress.github.io/sqlite-database-integration/native-extension/blueprint.json --verbosity=quiet

Note: composer run check-cs could not run in this workspace because vendor/bin/phpcs is not installed locally; CI runs it with dependencies installed.