v3.5.0 — Signature underline & watermark rotation fixes

Fixes

• Sign PDF: the underline beneath a typed signature now sizes to the actual rendered text width instead of the dragged box width — it ends exactly where the last letter ends instead of overshooting.
• Add Watermark: the rotation direction shown in the live drag/rotate preview now exactly matches the direction baked into the exported PDF, for both text and image/logo watermarks. Previously the two could tilt in opposite directions.