fix(pdf): classify unsafe text states

[McanKul]

Summary

• track text rise and report non-default rise as TEXT_RISE while returning shifted bounds
• track rendering mode and report non-default modes as TEXT_RENDER_MODE
• apply text clipping modes only after ET so later occurrences cannot be falsely classified as supported
• reject malformed Ts and Tr operands with a recoverable content error
• keep this read-only: no UI, mutation, save path, release, or main-branch changes

Verification

• cargo test --lib source_content — 68 passed
• cargo test --lib — 325 passed
• cargo clippy --lib --tests — no new warnings attributable to this change

Refs #33