[PHP] Use path helpers for runtime and pull artifacts

[adamziel]

Runtime and pull artifacts now use the existing path helpers, so a trailing output-directory slash produces stable artifact paths instead of duplicate separators.

The change routes host-side artifact and state paths through wp_join_unix_paths() and routes export list normalization through trim_right_slash(). SQLite integration lookup paths remain direct because the packaged CLI uses phar:// URIs, whose required :/// separator the Unix filesystem helper would collapse. Generated runtime URI code and bootstrap loader paths also remain direct because they do not share the same filesystem-path contract or helper availability.

Tests: cd tests && ../vendor/bin/phpunit Import/SqliteRuntimePluginCopyTest.php Import/NewSiteUrlSqliteTest.php Import/DeactivateHostPluginsTest.php Import/PlaygroundRemoteUploadProxyRuntimeTest.php --testdox --colors=never; PHPStan; PHP compatibility checks.

[github-actions]

Pull pipeline performance — large-directory

Site: large-directory · 2,000+ plus targeted file-transfer scenarios files · 10,000 posts · 25,000 postmeta · PHP 8.5.9

Stage	PR	trunk	Δ	Status	Details
playground-sqlite-db-pull	9.47 s	9.07 s	⚪ +395 ms (+4.4%)	✓	condition=db-pull in PHP.wasm runtime=php.wasm 8.3 wp_mysql_parser=enabled mode=lexer native_lexer=verified native_token_stream=WP_MySQL_Native_Token_Stream native_token_count=18 native_parser=selected trunk: condition=db-pull in PHP.wasm runtime=php.wasm 8.3 wp_mysql_parser=enabled mode=lexer native_lexer=verified native_token_stream=WP_MySQL_Native_Token_Stream native_token_count=18 native_parser=selected
playground-sqlite-db-apply	3.49 s	3.51 s	⚪ -18 ms (-0.5%)	✓	condition=db-apply to SQLite in PHP.wasm runtime=php.wasm 8.3 wp_mysql_parser=enabled mode=parser native_lexer=verified native_token_stream=WP_MySQL_Native_Token_Stream native_token_count=18 native_parser=verified native_ast=WP_MySQL_Native_Parser_Node sqlite_driver_parser=verified trunk: condition=db-apply to SQLite in PHP.wasm runtime=php.wasm 8.3 wp_mysql_parser=enabled mode=parser native_lexer=verified native_token_stream=WP_MySQL_Native_Token_Stream native_token_count=18 native_parser=verified native_ast=WP_MySQL_Native_Parser_Node sqlite_driver_parser=verified
Total	12.96 s	12.58 s	⚪ +377 ms (+3.0%)

_{Numbers carry runner noise; treat single-run deltas as directional, not authoritative.}

_{📈 Trunk performance history — commit-by-commit timeline.}