[PHP] Prepare cautious URL mappings once

[adamziel]

Prepares cautious URL mappings once per StructuredDataUrlRewriter instead of rebuilding them for each text leaf.

CautiousURLBaseRewriteMapping now owns URL validation, longest-source ordering, and pattern construction. Low-level cautious processors require that prepared object, so callers cannot accidentally rebuild the same mapping for every text value. Plain-text and block-markup processors share the one object created by StructuredDataUrlRewriter.

On the local benchmark, constructing a processor with one mapping fell from 1.75 µs to 0.09 µs. With 64 mappings it fell from 106 µs to 0.09 µs. Rewriting one short matching value fell from 3.23 µs to 1.37 µs.

Testing

The URL rewriting suite passes with 363 tests and 2,502 assertions. The focused cautious and structured suites pass with 180 tests and 219 assertions. PHPStan and the coding-standard checks pass for the changed classes.

[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	9.86 s	9.67 s	⚪ +187 ms (+1.9%)	✓	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	3.82 s	3.70 s	⚪ +114 ms (+3.1%)	✓	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	13.68 s	13.38 s	⚪ +300 ms (+2.2%)

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

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