Integrate rustedbytes-tl 0.3 through an explicit optional parser

[egorsmkv]

Closes #17 with a tested optional integration of the now-published rustedbytes-tl 0.3.0.

Add the non-default tl-parser feature, owned TlDocument and borrowing TlElement APIs, plus HtmlResponse::tl_document(). The response adapter snapshots the existing decoded, byte-limited source; callers keep the document for repeated and nested queries. It uses TL's safe owned constructor and preserves selector errors separately from empty results. Text decoding is enabled; raw_attr deliberately exposes raw attribute spelling. No unsafe code is introduced.

Existing scraper-based selection, compiled scraper::Selector APIs, utility return types, XPath and default dependency behavior remain unchanged. This is an explicit alternative, not transparent HTML5 equivalence: omitted tbody, malformed-tree recovery, raw attributes, serialization and unsupported CSS still differ. There is no automatic fallback. Test site fixtures before opting in.

Update the independent evaluation to exact published TL 0.3.0 + entities. The catalog's 14 checked selectors and decoded entity text now agree with scraper 0.27.0; retain tests demonstrating remaining differences. Document ownership, lifetimes, memory/parse boundaries and limitations. Add TL feature checks and a path-filtered independent evaluation workflow. Historical timings are clearly labeled as TL 0.2.0, not performance evidence for this adapter.

Validation:

• Rust 1.99: 126 default unit tests, 131 with tl-parser, 131 no-default + tl-parser, 133 all-features; all passed. Enabled TL doctests and lifetime compile-fail test passed.
• Adapter tests cover nested selection, decoded text, raw/boolean attributes, rejected versus empty queries, zero/byte limits, HTTP charset decoding, response mutation/drop, Send/Sync and moving the owner to a worker.
• Rust 1.92: root check --all-targets --features tl-parser and strict Clippy passed; independent evaluation compilation passed.
• Five differential tests, audit executable, independent strict Clippy and all 15 Criterion smoke cases passed.
• Root all-target compilation, documentation build and 34 Markdown examples in three feature configurations passed. Rust 1.99 lint/doc commands allow only its pre-existing fetch_update deprecation; Rust 1.92 Clippy passes without allowances.
• Formatting, diff checks and actionlint passed. Native TLS verification used cmake/libclang with local PATH and include-path setup.

No new timing, allocation or whole-crawler speedup claim is made. A broad real-site differential corpus and complete-adapter benchmarks remain prerequisites for replacing scraper as the default. GitHub Actions results are pending.