feat(parser): add HTML support

[rabii-chaarani]

Summary

• register HTML discovery for .html and .htm
• add the Tree-sitter HTML grammar, named-node syntax catalog, CLI, and MCP exposure
• preserve complete ordered markup syntax without inventing component ontology mappings
• document the conservative parsing contract in k-wiki

Verification

• cargo fmt --check
• cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
• cargo test --workspace --locked
• cargo publish --dry-run --locked
• exact crate-size gate
• recommended wiki validation, link check, and site build

[rabii-chaarani]

Superseded by #107, which combines TypeScript/TSX, JavaScript/JSX, and HTML on top of the merged CSS support in one atomic PR.